Electric compression and expansion apparatus and air conditioning system including the same

ABSTRACT

The present disclosure provides an electric compression and expansion apparatus comprising a main housing comprising a motor chamber, a motor part housed in the motor chamber, a rotary shaft part extending in a length direction and coupled to the motor part, a compression part coupled to one side of the rotary shaft part in the length direction, and an expansion part coupled to another side of the rotary shaft part in the length direction. The rotary shaft part is configured to rotate integrally with the motor part, and the compression part is configured to rotate integrally with the rotary shaft part to compress refrigerant. The expansion part is configured to rotate integrally with the rotary shaft part to expand the compressed refrigerant.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority under 35 U.S.C. § 119(a)to Korean Patent Application No. 10-2019-0058928, filed on May 20, 2019,the disclosure of which is incorporated by reference herein in itsentirety.

BACKGROUND 1. Technical Field

The present disclosure relates to an electric compression and expansionapparatus and an air conditioning system including the same, and moreparticularly, to an electric compression and expansion apparatus capableof operating a compressor for compressing refrigerant and an expanderfor expanding refrigerant using one power source and an air conditioningsystem including the same.

2. Description of the Related Art

Compressors serving to compress refrigerant in air conditioning systemsfor vehicle have been developed in various forms. In recent years,electric compressors (motor-operated compressors) driven by electricpower using motors have been actively developed due to the tendency ofelectrification of vehicle components.

A motor-operated compressor generally employs a scroll-compressionmethod which is suitable for a high compression ratio operation. Such ascroll-type motor-operated compressor (hereinafter, referred to as“motor-operated compressor”) includes a motor part, a compression part,and a rotating shaft connecting the motor part and the compression part.

Specifically, the motor part is configured as a rotary motor or thelike, and installed inside a hermetic casing. The compression part islocated at one side of the motor part, and is provided with a fixedscroll and an orbiting scroll. The rotating shaft is configured totransmit rotational force of the motor part to the compression part.

The refrigerant compressed in the compression part is exhausted tooutside of the electric compressor through an exhaust port. Theexhausted refrigerant is utilized for operating an air conditioningsystem for vehicle.

A vehicle air conditioning system includes various devices forexchanging heat through phase change of refrigerant in addition to theabove-described electric compressor.

That is, referring to FIG. 1, an air conditioning system 1000 accordingto the related art includes a compressor 1100 for compressingrefrigerant, a condenser 1200 for condensing refrigerant, an expander1300 for expanding refrigerant, an evaporator 1400 for evaporatingrefrigerant, and the like. The components form a refrigerant cycle fordriving a vehicle air conditioning system.

Among the components, the expander 1300 serves to expandhigh-temperature high-pressure refrigerant having passed through thecondenser 1200 and convert the expansion of the refrigerant into shaftpower. It is preferable that a rate at which the expander 1300 expandsrefrigerant should depend on the rotational rate of the compressor 1100.

That is, the expansion of the refrigerant by the expander 1300 tocorrespond to the rate at which the refrigerant is compressed in thecompressor 1100 is advantageous for improving the air conditioningefficiency of the air conditioning system 1000.

However, it is difficult for conventional expanders to operate accordingto the refrigerant compression rate of an electric compressor thatchanges in real time. This is due to the complexity of a manufacturingprocess and the increase in manufacturing cost.

Accordingly, typically, conventional expanders are operated at constantrate having the best expansion efficiency rather than depending on therefrigerant compression rate of an electric compressor.

Such a driving scheme can secure expansion efficiency to some extent,but it is hard to say that it always has a favorable effect on improvingthe air conditioning efficiency of the overall air conditioning system.This is because in addition to the refrigerant expansion rate of anexpander, there are many variables to consider when the air conditioningsystem is driven.

Korean Patent No. 10-1764158 discloses an integral compressor-expander.In detail, the document discloses an integral compressor-expander havinga structure that connects a compressor and an expander by one shaft suchthat the expander may be rotated according to an operating mode of thecompressor.

However, this type of integral compressor-expander has a disadvantage inthat an apparatus for providing power to drive the compressor and theexpander should be located outside a casing thereof. This can lead to anincrease in volume throughout the system. That is, there is a limitationin that it is difficult to apply to a vehicle air conditioning systemfor which product miniaturization is important.

Furthermore, in the case of the above type of integralcompressor-expander, refrigerant may be moved between a compressor andan expander housed in the same casing. Also, there is another limitationin which no means for resolving a reduction in compression efficiencyand a reduction in expansion efficiency which may be caused in this caseis considered.

Korean Patent No. 10-1764158 discloses a combined scrollexpander-compressor. In detail, this document discloses a combinedscroll expander-having a structure in which the rotation of a scrollexpander is interlocked with the rotation of a scroll compressor byconnecting an orbiting scroll of the scroll expander and an orbitingscroll of the scroll compressor through a power transfer means.

However, this type of combined scroll compressor-expander has alimitation in that an apparatus for providing power to rotate a scrollexpander and a scroll compressor should be located outside a casingthereof. This causes an increase in volume throughout the system, andthus the combined scroll compressor-expander also has a limitation inthat it is difficult to apply to a vehicle air conditioning system.

Furthermore, in the case of the above type of combined scrollexpander-compressor, a structure for enabling a back-pressure chamber ofa scroll compressor to communicate with a back-pressure chamber of ascroll expander is considered. However, there is a limitation in that nomeans for preventing unintended effects from occurring betweenrefrigerants housed in the back pressure chambers is considered.

RELATED ART DOCUMENTS Patent Documents

-   (Patent Document 1) Korean Patent No. 10-1764158 (Aug. 14, 2017)-   (Patent Document 2) Korean Patent No. 10-0842301 (Jun. 30, 2008)

SUMMARY

Therefore, an aspect of the detailed description is to provide anelectric compression and expansion apparatus capable of solving theabove problems and an air conditioning system including the same.

First, the present disclosure is directed to providing an electriccompression and expansion apparatus and an air conditioning systemstructured not to require an excessive increase in size in order to haveboth of a compression part for compressing refrigerant and an expansionpart for expanding refrigerant.

Also, the present disclosure is directed to providing an electriccompression and expansion apparatus structured to minimize the sizes ofelements constituting an air conditioning system and the size of the airconditioning system, and an air conditioning system including the same.

Also, the present disclosure is directed to providing an electriccompression and expansion apparatus and an air conditioning systemstructured to enable a rate at which refrigerant is compressed in thecompression part to interoperate with a rate at which refrigerant isexpanded in the expansion part.

Also, the present disclosure is directed to providing an electriccompression and expansion apparatus structured to provide power for acompression part to compress refrigerant and power for an expansion partto expand refrigerant by using a single power source, and an airconditioning system including the same.

Also, the present disclosure is directed to providing an electriccompression and expansion apparatus structured to decrease powerrequired to operate an air conditioning system, and an air conditioningsystem including the same.

Also, the present disclosure is directed to providing an electriccompression and expansion apparatus structured to enable a back pressurechamber of a compression part and a back pressure chamber of anexpansion part to communicate with each other, and an air conditioningsystem including the same.

Also, the present disclosure is directed to providing an electriccompression and expansion apparatus structured to adjust whether toallow communication between back pressure chambers of a compression partand an expansion part depending on pressures in the back pressurechambers, and an air conditioning system including the same.

In order to achieve the objectives of the present disclosure, there isprovided an electric compression and expansion apparatus comprising amain housing comprising a motor chamber; a motor part housed in themotor chamber; a rotary shaft part extending in a length direction andcoupled to the motor part, wherein the rotary shaft part is configuredto rotate integrally with the motor part; a compression part coupled toone side of the rotary shaft part in the length direction, wherein thecompression part is configured to rotate integrally with the rotaryshaft part to compress refrigerant; and an expansion part coupled toanother side of the rotary shaft part in the length direction, whereinthe expansion part is configured to rotate integrally with the rotaryshaft part to expand the compressed refrigerant.

Also, the main housing of the electric compression and expansionapparatus may comprise an intake port configured to introduce therefrigerant into the main housing, and a rear housing comprising anexhaust port located on one side of the compression part opposite to themain housing, the exhaust port being configured to discharge thecompressed refrigerant.

Also, the compression part of the electric compression and expansionapparatus may comprise a first orbiting scroll coupled to the rotaryshaft part and configured to rotate integrally with the rotary shaftpart; and a first fixed scroll located on one side of the first orbitingscroll opposite to the main housing, wherein the first fixed scroll isconfigured to be brought into contact with the first orbiting scrollwith a predetermined space formed therein, and wherein the first fixedscroll is configured to compress the refrigerant. The expansion part maycomprise a second orbiting scroll coupled to the rotary shaft part andconfigured to rotate integrally with the rotary shaft part; and a secondfixed scroll located on one side of the second orbiting scroll oppositeto the main housing, wherein the second fixed scroll is configured to bebrought into contact with the second orbiting scroll with apredetermined space formed therein, and wherein the second fixed scrollis configured to expand the compressed refrigerant. The second fixedscroll may comprise an intake hole configured to introduce thecompressed refrigerant into the predetermined space.

Also, the electric compression and expansion apparatus may furthercomprise a first main frame located between the main housing and thecompression part, the first main frame being configured to couple themain housing to and in fluid communication with the compression part;and a second main frame located between the main housing and theexpansion part, the second main frame being configured to supportanother side of the rotary shaft part facing the expansion part.

Also, the first main frame of the electric compression and expansionapparatus may comprise a first bearing surrounding an outercircumference on one side of the rotary shaft part facing thecompression part, the first bearing being configured to support the oneside of the rotary shaft part. The second main frame may comprise asecond bearing surrounding the outer circumference on the another sideof the rotary shaft part facing the expansion part, the second bearingbeing configured to support the another side of the rotary shaft part.The first bearing may have a smaller inner diameter than the secondbearing.

Also, a refrigerant communication flow path may be formed through therotary shaft part in the length direction, one side of the refrigerantcommunication flow path facing the compression part may be incommunication with an inner space of the first main frame, and anotherside of the refrigerant communication flow path facing the expansionpart may be in communication with an inner space of the second mainframe.

Also, the first main frame may comprise a first balance weightconfigured to rotate together with the rotary shaft part and thecompression part, and one side of the first balance weight may becoupled to one end of the rotary shaft part facing the compression partand another side of the first balance weight opposite to the one sidemay be coupled to the compression part.

Also, the first balance weight of the electric compression and expansionapparatus may comprise a first body part comprising one side configuredto be brought into contact with one end of the rotary shaft part; afirst eccentric part extending from the first body part; and a firstspace part formed through the first body part, wherein a first fasteningpin for coupling the first balance weight to the one end of the rotaryshaft is configured to be inserted into the first space part. The oneside of the first body part may comprise a first communication holerecessed and configured to form a space to enable the inner space of thefirst main frame and the refrigerant communication flow path tocommunicate with each other.

Also, a second balance weight may be located inside the second mainframe, the second balance weight being configured to rotate togetherwith the rotary shaft part and the expansion part. One side of thesecond balance weight may be coupled to another end of the rotary shaftpart facing the expansion part and another side coupled to the expansionpart and opposite to the one side.

Also, the refrigerant communication flow path may comprise a check valveconfigured to restrict a flow of refrigerant inside the refrigerantcommunication flow path to a direction from the first main frame to thesecond main frame.

Also, the second balance weight of the electric compression andexpansion apparatus may comprise a second body part having one sideconfigured to be brought into contact with the another end of the rotaryshaft part; and a second eccentric part extending from the second bodypart. The one side of the second body part may comprise a secondcommunication hole recessed and configured to form a space to enable theinner space of the second main frame and the refrigerant communicationflow path to communicate with each other.

Also, the second balance weight of the electric compression andexpansion apparatus may comprise a second body part having one sideconfigured to be brought into contact with the another end of the rotaryshaft part; a second protrusion part protruding a predetermined distancefrom the another side of the second body part opposite to the one sideof the second body part; and a second eccentric part extending from thesecond body part. The second protrusion part may comprise a second spacepart recessed a predetermined distance from the one side of the secondbody part, wherein a second fastening pin for coupling the protrusionpart to the other end of the rotary shaft part is configured to beinserted into the second space part; and a closed surface located on oneside of the second protrusion part opposite to the one side of thesecond body part, the closed surface being configured to close thesecond space part.

Also, when the pressure in the first main frame is greater than or equalto the pressure in the second main frame, the second balance weight ofthe electric compression and expansion apparatus is configured to move apredetermined distance toward the expansion part such that therefrigerant communication flow path communicates with the inner space ofthe second main frame, and when the pressure in the first main frame issmaller than the pressure in the second main frame, the second balanceweight of the electric compression and expansion apparatus is configuredto move a predetermined distance toward the main housing such that thecommunication between the refrigerant communication flow path and theinner space of the second main frame is blocked.

Also, there is provided an air conditioning system comprising anelectric compression and expansion apparatus configured to be driven bypower and configured to compress or expand refrigerant; a condensercoupled to and in fluid communication with the electric compression andexpansion apparatus, the condenser being configured to condenserefrigerant compressed in the electric compression and expansionapparatus; and an evaporator coupled to and in fluid communication withthe electric compression and expansion apparatus, the evaporator beingconfigured to evaporate refrigerant expanded in the electric compressionand expansion apparatus. The electric compression and expansionapparatus may comprise a main housing comprising a motor chamber; amotor part housed in the motor chamber; a rotary shaft part extending ina length direction and coupled to the motor part, wherein the rotaryshaft part is configured to rotate integrally with the motor part; acompression part coupled to one side of the rotary shaft part in thelength direction, wherein the compression part is configured to rotateintegrally with the rotary shaft part to compress refrigerant; and anexpansion part coupled to the another side of the rotary shaft part inthe length direction, wherein the expansion part is configured to rotateintegrally with the rotary shaft part to expand the compressedrefrigerant.

Also, the electric compression and expansion apparatus of the airconditioning system may comprise a first main frame located between themain housing and the compression part, the first main frame beingconfigured to couple the main housing to and in fluid communication withthe compression part; and a second main frame located between the mainhousing and the expansion part, the second main frame being configuredto support the other side of the rotary shaft part facing the expansionpart, and a refrigerant communication flow path formed through therotary shaft part in the length direction thereof. One side of therefrigerant communication flow path facing the compression part may bein communication with an inner space of the first main frame, andanother side of the refrigerant communication flow path facing theexpansion part may be in communication with an inner space of the secondmain frame.

According to the present disclosure, the following effects can beobtained.

First, the compression part and the expansion part may be housed in thefirst main frame and the second main frame, respectively. The mainhousing may just have a space to occupy the motor chamber for housingthe motor part, and thus it may be possible for the main housing todecrease in size. The first main frame and the second main frame mayjust house the compression part and the expansion part, respectively,and thus it may be possible to decrease the size of the main frames.

Accordingly, even though both of the compression part and the expansionpart are provided, the electric compression and expansion apparatus maynot excessively increase in size.

Also, among the elements constituting the air conditioning system, thecompression part and the expansion part may be integrated in theelectric compression and expansion apparatus. The electric compressionand expansion apparatus may not increase in size although it can performboth compression and expansion of refrigerant.

Accordingly, the number of elements constituting the air conditioningsystem may decrease, and also an element for compressing or expandingrefrigerant may decrease in size. As a result, it may be possible tominimize the air conditioning system compared to a case where thecompressor and the expander are separately provided.

Also, the first orbiting scroll of the compression part and the secondorbiting scroll of the expansion part may be coupled to the same rotaryshaft. When the rotary shaft is rotated by the motor part, the firstorbiting scroll and the second orbiting scroll may be rotated at thesame rate as those of the rotary shaft and the motor part.

Therefore, a rate at which refrigerant is compressed in the compressionpart and a rate at which refrigerant is expanded in the expansion partmay be interoperable. As a result, the refrigerant expansion rate of theexpansion part may interoperate with the refrigerant compression rate ofthe compression part, and thus it may be possible to improve the airconditioning efficiency of the air conditioning system.

Also, the rotary shaft to which the first orbiting scroll of thecompression part and the second orbiting scroll of the expansion partare connected may be driven by the single motor part.

Accordingly, no separate power sources may be required for driving thefirst orbiting scroll and the second orbiting scroll. As a result, itmay be possible to reduce power required to drive the electriccompression and expansion apparatus. Accordingly, the entire powerconsumption of the air conditioning system may be reduced, and thus itmay be possible to improve air conditioning efficiency.

Also, the refrigerant communication flow path may be formed on therotary shaft. The refrigerant communication flow path may communicatewith a first back pressure chamber of the compression part located inthe first main frame and a second back pressure chamber of the expansionpart located in the second main frame.

Accordingly, high-pressure refrigerant staying in the first backpressure chamber may be introduced into the second back pressure chamberthrough the refrigerant communication flow path. Accordingly, it may bepossible to quickly form a back pressure necessary for the expansionpart to expand refrigerant. As a result, it may be possible to improveexpansion efficiency at which the expansion part expands refrigerant.

Also, the check valve may be provided in the refrigerant communicationflow path of the rotary shaft. The check value may control refrigerantflow such that refrigerant can flow from the first back pressure chamberto the second back pressure chamber when the pressure in the first backpressure chamber is greater than the pressure in the second backpressure chamber.

Accordingly, when the pressure in the first back pressure chamber issmaller than the pressure in the second back pressure chamber,refrigerant may be prevented from flowing from the second back pressurechamber to the first back pressure chamber. Accordingly, a back pressuresufficient to compress refrigerant may be formed in the first backpressure chamber of the compression part, and thus it may be possible toimprove the compression efficiency of the refrigerant.

Also, the closed surface may be provided in the second balance weightcoupled to the second end of the rotary shaft facing the expansion part.When the pressure in the first back pressure chamber is greater than thepressure in the second back pressure chamber, the second balance weightmay be spaced apart from the second end of the rotary shaft.Accordingly, the refrigerant communication flow path may communicatewith the second back pressure flow path.

Also, when the pressure in the first back pressure chamber is smallerthan the pressure in the second back pressure chamber, the secondbalance weight may be brought into contact with the second end of therotary shaft. Accordingly, the refrigerant communication flow path maybe blocked by the closed surface, and the refrigerant communication flowpath and the second back pressure chamber may not communicate with eachother.

Accordingly, only when the pressure in the first back pressure chamberis greater than the pressure in the second back pressure chamber, thefirst back pressure chamber, the second back pressure chamber, and therefrigerant communication flow path may communicate with each other.Accordingly, a back pressure sufficient to compress refrigerant may beformed in the first back pressure chamber of the compression part, andthus it may be possible to improve the compression efficiency of therefrigerant.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing an air conditioning cycleaccording to a related art.

FIG. 2 is a perspective view showing an electric compression andexpansion apparatus according to an embodiment of the presentdisclosure.

FIG. 3 is an exploded perspective view of the electric compression andexpansion apparatus of FIG. 2 according to an embodiment of the presentdisclosure.

FIG. 4A is a cross-sectional view of an electric compression andexpansion apparatus according to an embodiment of the presentdisclosure.

FIG. 4B is another cross-sectional view of the electric compression andexpansion apparatus of FIG. 4A according to an embodiment of the presentdisclosure.

FIG. 5A is a perspective view of a balance weight provided in theelectric compression and expansion apparatus of FIGS. 4A and 4Baccording to an embodiment of the present disclosure.

FIG. 5B is another perspective view of the balance weight provided inthe electric compression and expansion apparatus of FIGS. 4A and 4Baccording to an embodiment of the present disclosure.

FIG. 6A is a cross-sectional view of an electric compression andexpansion apparatus according to an embodiment of the presentdisclosure.

FIG. 6B is another cross-sectional view of the electric compression andexpansion apparatus of FIG. 6A according to an embodiment of the presentdisclosure.

FIG. 7A is a perspective view of a balance weight provided in arefrigerant expansion part of the electric compression and expansionapparatus of FIG. 6 according to an embodiment of the presentdisclosure.

FIG. 7B is another perspective view of the balance weight provided in arefrigerant expansion part of the electric compression and expansionapparatus of FIG. 6 according to an embodiment of the presentdisclosure.

FIG. 8 is a schematic diagram showing a flow of refrigerant when a firstback pressure chamber and a second back pressure chamber communicatewith each other in the electric compression and expansion apparatus ofFIGS. 4A and 4B according to an embodiment of the present disclosure.

FIG. 9 is a schematic diagram showing a flow of refrigerant when a firstback pressure chamber and a second back pressure chamber do notcommunicate with each other in the electric compression and expansionapparatus of FIGS. 4A and 4B according to an embodiment of the presentdisclosure.

FIG. 10 is a schematic diagram showing a flow of refrigerant when afirst back pressure chamber and a second back pressure chambercommunicate with each other in the electric compression and expansionapparatus of FIGS. 6A and 6B according to an embodiment of the presentdisclosure.

FIG. 11 is a schematic diagram showing a flow of refrigerant when afirst back pressure chamber and a second back pressure chamber do notcommunicate with each other in the electric compression and expansionapparatus of FIGS. 6A and 6B according to an embodiment of the presentdisclosure.

FIG. 12 is a schematic diagram showing the components of a refrigerantcycle for driving a vehicle air conditioning system according to anembodiment of the present disclosure.

DETAILED DESCRIPTION OF THE EMBODIMENTS

An electric compression and expansion apparatus and an air conditioningsystem including the same according to an embodiment of the presentdisclosure will be described in detail below with reference to theaccompanying drawings.

In the following description, some elements may be omitted so as toclarify the features of the present disclosure.

FIGS. 4A and 4B show cross-sectional views according to the sameembodiment, but are presented as a plurality of drawings.

Likewise, FIGS. 6A and 6B show cross-sectional views according to thesame embodiment, but are presented as a plurality of drawings.

It will be understood that when an element is referred to as being“connected with” another element, the element can be connected with theanother element or intervening elements may also be present.

In contrast, when an element is referred to as being “directly connectedwith” another element, there are no intervening elements present.

A singular representation may include a plural representation unless itrepresents a definitely different meaning from the context.

The term “refrigerant” as used herein refers to any medium that takesheat away from a low-temperature object and transport the heat to ahigh-temperature object. In an embodiment, the refrigerant may includecarbon dioxide (CO2), R134a, R1234yf, and the like.

The terms “front,” “rear,” “upper,” “lower,” “right,” and “left” as usedherein will be understood with reference to the coordinate systems shownin FIGS. 2 and 3.

The electric compression and expansion apparatus 10 according to anembodiment of the present disclosure may function as an element of anair conditioning system 1 to be described below. The electriccompression and expansion apparatus 10 may comprise a compression part600 for compressing refrigerant and an expansion part 700 for expandingrefrigerant. Accordingly, it may be possible to simplify the structureof and miniaturize the size of the air conditioning system 1.

In the following description, the electric compression and expansionapparatus 10 according to an embodiment of the present disclosure willbe described first, and then the air conditioning system 1 including theelectric compression and expansion apparatus 10 will be described.

Referring to FIGS. 2 to 7, the electric compression and expansionapparatus 10 according to an embodiment of the present disclosure maycomprise a main housing 100, a rear housing 200, a motor part 300, arotary shaft part 400, a frame part 500, the compression part 600, andthe expansion part 700, and a refrigerant flow adjustment part 800.

The main housing 100 may form a portion of the external appearance ofthe electric compression and expansion apparatus 10. Also, the mainhousing 100 may form the body of the electric compression and expansionapparatus 10 and may have a space formed therein.

In an embodiment, the motor part 300, the rotary shaft part 400, andother devices for driving the electric compression and expansionapparatus 10 may be housed in the space. In the shown embodiment, thecompression part 600 and the expansion part 700 may be located outsidethe main housing 100. Alternatively, the compression part 600 and theexpansion part 700 may be located inside the main housing 100.

In an embodiment, the main housing 100 may comprise the frame part 500to be described below. That is, the frame part 500 may not be separatelyprovided, and the main housing 100 may function as the frame part 500.

In the above embodiment, the size of the main housing 100 may beincreased by the size of the frame part 500 compared to the shownembodiment.

The main housing 100 may have a circular cross-section and may have acylindrical shape extending lengthwise. The main housing 100 may haveany shape capable of housing the motor part 300 and the rotary shaftpart 400.

However, considering that the motor part 300 can be rotated inside themain housing 100 to compress refrigerant, the main housing 100 may beformed to have a circular cross shape with high pressure resistance.

A first main frame 510 of the frame part 500 may be located on one sideof the main housing, that is, on the front side in the shown embodiment.Also, a second main frame 520 of the frame part 500 may be located onthe other side of the main housing 100 opposite to the one side, thatis, on the rear side in the shown embodiment.

The main housing 100 may communicate with the first main frame 510.Refrigerant introduced into the main housing 100 may be moved toward thecompression part 600 through the first main frame 510.

The main housing 100 may communicate with the second main frame 520.Thus, refrigerant introduced into the expansion part 700 may bepartially introduced into the main housing 100 to prevent excessivepressure from occurring in the expansion part 700.

Alternatively, the main housing 100 may not be configured to communicatewith the second main frame 520. In this case, a separate sealing memberfor preventing communication between the main housing 100 and the secondmain frame 520 may be provided at a portion where the main housing 100and the second main frame 520 communicate with each other.

The main housing 100 may comprise a motor chamber 110 and an intake port120.

The motor chamber 110 may be a space where the motor part 300 isrotatably housed. The motor chamber 110 may be defined as an inner spaceof the main housing 100. The outer circumferential surface of the motorchamber 110 may be defined by the inner circumferential surface of themain housing 100.

Alternatively, a separate housing (not shown) may be provided to formthe motor chamber 110. The housing (not shown) may be housed in the mainhousing 100. In this case, the outer circumferential surface of thehousing (not shown) may be brought into contact with the maincircumferential surface of the main housing 100.

When the motor part 300 is housed in the motor chamber 110, the outercircumferential surface of a stator 310 forming the outside of the motorpart 300 may be brought into contact with the outer circumferentialsurface of the motor chamber 110. Accordingly, the stator 310 may befixed in the motor chamber 110 and remain stationary regardless of therotation of a rotor 320.

In an embodiment that is not shown, a protrusion (not shown) may beformed on the outer circumferential surface of the motor chamber 110,and a blind hole (not shown) may be recessed from the outercircumferential surface of the stator 310. In the above embodiment, themotor part 300 may be housed in the motor chamber 110 such that theprotrusion (not shown) can be fitted into the blind hole (not shown).

The intake port 120 may enable the inside and outside of the mainhousing 100 to communicate with each other. Refrigerant outside theelectric compression and expansion apparatus 10 may be introduced intothe main housing 100 through the intake port 120.

The introduced refrigerant may be compressed through the first mainframe 510 and the compression part 600. The compressed refrigerant maybe discharged to the outside of the electric compression and expansionapparatus 10 through an exhaust port 212 of the rear housing 200.

The intake port 120 may be located on the outer circumferential surfaceof the main housing 100. The intake port 120 may be in the form of athrough-hole passing through the main housing 100.

The rear housing 200 may form a portion of the external appearance ofthe electric compression and expansion apparatus 10. In detail, the rearhousing 200 may form a portion of the external appearance on one side ofthe main housing 100, that is, on the front side in the shownembodiment.

In the shown embodiment, the first main frame 510 of the frame part 500and a first fixed scroll 620 of the compression part 600 may be locatedbetween the rear housing 200 and the main housing 100. That is, thefirst main frame 510, the first fixed scroll 620, and the rear housing200 may be sequentially located in a direction from the main housing 100toward the front side.

In the embodiment in which the first main frame 510 is included in themain housing 100 and the compression part 600 is housed in the mainhousing 100 as described above, the rear housing 200 may be located incontact with the main housing 100.

The rear housing 200 may communicate with the main housing 100. Indetail, the rear housing 200 may communicate with the first fixed scroll620 and the first main frame 510. The refrigerant compressed in thecompression part 600 through the main housing 100 and the first mainframe 510 may be discharged through the exhaust port 212 of the rearhousing 200.

In the shown embodiment, the rear housing 200 has the shape of a caphaving a circular cross-section. The rear housing 200 may have any shapecapable of coupling to the first fixed scroll 620.

The rear housing 200 may comprise an exhaust flow path 210, an oildischarge flow path 220, and a discharge chamber 230.

The exhaust flow path 210 may be a passage through which the refrigerantcompressed in the compression part 600 can be discharged. The exhaustflow path 210 may communicate with the discharge chamber 230.

The exhaust port 212 configured to enable the inside and outside of therear housing 200 to communicate with each other may be formed on one endof the exhaust flow path 210, that is, an upper end of the exhaust flowpath 210 in the shown embodiment. In an embodiment, the exhaust port 212may be provided in the form of a through-hole for enabling the insideand outside of the rear housing 200 to communicate with each other.

The compressed refrigerant may flow toward the exhaust flow path 210 viathe discharge chamber 230. The refrigerant having entered the exhaustflow path 210 may be discharged to the outside of the electriccompression and expansion apparatus 10 through the exhaust port 212.

In this case, the refrigerant introduced into the exhaust flow path 210may be mixed with oil. When oil remains in the refrigerant dischargedthrough the exhaust port 212, there may be a possibility that thecooling efficiency of the air conditioning system 1 may fall.Furthermore, the oil remaining in the refrigerant may damage someapparatuses included in the air conditioning system 1.

Thus, a cyclone apparatus (not shown) or the like configured to separateoil from refrigerant may be provided inside the exhaust flow path 210.

The oil discharge flow path 220 may be a flow path through which the oilseparated from the refrigerant can move. The oil discharge flow path 220may communicate with the exhaust flow path 210. A residual mixture ofthe refrigerant and the oil and the oil separated from the refrigerantin the exhaust flow path 210 may move to a lower side of the rearhousing 200 through the oil discharge flow path 220.

The oil discharge flow path 220 may communicate with an oil flow pathpart (not shown) outside the rear housing 200. The residual mixture ofthe refrigerant and the coil or the oil having moved to the lower sideof the rear housing 200 may flow back to the compression part 600through the oil flow path part (not shown).

The discharge chamber 230 may be a space through which the refrigerantcompressed in the compression part 600 can pass before being dischargedthrough the exhaust port 212. The discharge chamber 230 may be formed onone side of the rear housing 200 adjacent to the first main frame 510.The refrigerant compressed in the compression part 600 may be under highpressure. When high-pressure refrigerant is directly discharged to theoutside of the electric compression and expansion apparatus 10 throughthe exhaust port 212, other devices included in the air conditioningsystem 1 may be damaged.

Thus, the discharge chamber 230 may be configured such that the pressureof the compressed refrigerant moves toward the exhaust port 212 andbecomes a predetermined pressure.

The discharge chamber 230 may communicate with the compression part 600.The compressed refrigerant may be introduced into the discharge chamber230. Also, the discharge chamber 230 may communicate with the exhaustflow path 210. The refrigerant discharged from the discharge chamber 230may flow into the exhaust flow path 210.

A discharge flow path member 231 may be provided in the dischargechamber 230. The discharge flow path member 231 may form a flow paththrough which the compressed refrigerant can be moved from thecompression part 600 to the exhaust flow path 210.

In the shown embodiment, the discharge flow path member 231 may beformed to protrude toward the compression part 600. The discharge flowpath member 231 may be provided in any form capable of forming a flowpath of the compressed refrigerant flowing in the discharge chamber 230.

The motor part 300 may provide power used by the compression part 600 tocompress refrigerant and power used by the expansion part 700 to expandrefrigerant. The motor part 300 may be configured to receive power and acontrol signal from a control unit (not shown) outside the electriccompression and expansion apparatus 10 and operate according to thepower and control signal. To this end, the motor part 300 may beelectrically conductively connected to the control unit (not shown).

In an embodiment, the control unit (not shown) may be provided insidethe electric compression and expansion apparatus 10. Even in this case,the motor part 300 may be electrically conductively connected to thecontrol unit (not shown) and configured to receive power and a controlsignal.

The motor part 300 may be connected to the compression part 600 and theexpansion part 700.

In detail, the motor part 300 may be connected to a first orbitingscroll 610 of the compression part 600. When the motor part 300 isrotated, the first orbiting scroll 610 may be rotated integrally withthe motor part 300 by the rotary shaft part 400.

Also, the motor part 300 may be connected to a second orbiting scroll710 of the expansion part 700. When the motor part 300 is rotated, thesecond orbiting scroll 710 may be rotated integrally with the motor part300 by the rotary shaft part 400.

The motor part 300 may be housed in the main housing 100. In detail, themotor part 300 may be housed in the motor chamber 110 such that theouter circumferential surface of the stator 310 forming the outside ofthe motor part 300 is brought into contact with the innercircumferential surface of the motor chamber 110.

With the above configuration, the stator 310 may be located in the mainhousing 100 while remaining stationary regardless of the rotation of therotor 320.

The motor part 300 may comprise the stator 310 and the rotor 320. Also,the motor part 300 may comprise an input part (not shown) for receivingpower and a control signal from an external control part (not shown).

The stator 310 may form an electromagnetic field according to thereceived power and control signal. The electromagnetic field formed bythe stator 310 may exert an electromagnetic force on a magnet includedin the rotor 320. Accordingly, when the rotor 320 is rotated, the firstorbiting scroll 610 and the second orbiting scroll 710 may be rotated.

The stator 310 may comprise a plurality of coils (not shown). The coils(not shown) may be wound around the stator 310. The coils may beconfigured such that currents of different phases flow therethrough. Inan embodiment, each coil (not shown) may be configured such that anelectric current having any one of U phase, V phase, and W phase flowstherethrough.

The stator 310 may form the outside of the motor part 300. That is, thestator 310 may be a portion at which the motor part 300 is exposed tothe outside. When the motor part 300 is housed in the motor chamber 110,the outer circumferential surface of the stator 310 may be brought intocontact with the motor chamber 110, that is, the inner circumferentialsurface of the main housing 100.

The stator 310 may be fixed in the motor chamber 110. When the power andcontrol signal are applied to the motor part 300, the plurality of coilsof the stator 310 may form an electromagnetic field. Thus, the stator310 may remain stationary although the rotor 320 is rotated.

In the shown embodiment, the stator 310 may have a circularcross-section and may have a cylindrical shape extending lengthwise (inthe front-rear direction). The shape of the stator 310 may be changed tocorrespond to the shape of the main housing 100.

A hollow portion may be formed inside the stator 310. The rotor 320 maybe rotatably housed in the hollow portion. The rotor 320 may be housedin the hollow portion such that the rotor 320 is spaced a predetermineddistance from the stator 310.

That is, the stator 310 and the rotor 320 may not be in contact witheach other. Accordingly, the rotor 320 may be rotated relative to thestator 310, and the stator 310 may remain stationary regardless of therotation of a rotor 320.

In the shown embodiment, the hollow portion may have a cylindrical shapeextending in the length direction (the front-rear direction) of thestator 310. The hollow portion may have any shape capable of housing therotor 320.

The rotor 320 may be rotated by an electromagnetic field formed by theplurality of coils of the stator 310. The rotor 320 may comprise aplurality of magnets (not shown).

When the plurality of coils (not shown) of the stator 310 form anelectromagnetic field, the plurality of magnets (not shown) of the rotor320 may be subjected to an electromagnetic force. By the electromagneticforce, the rotor 320 may be rotated clockwise or counterclockwise.

The rotor 320 may be rotatably housed in the hollow portion formedinside the stator 310. The rotor 320 may be disposed in the hollowportion and spaced a predetermined distance from the stator 310. Thatis, the outer circumferential surface of the rotor 320 and an innercircumferential surface of the stator 310 may not be in contact witheach other.

The rotary shaft part 400 may be installed through and coupled to therotor 320. The rotor 320 and the rotary shaft part 400 may be coaxiallyarranged.

When the rotor 320 is rotated, the rotary shaft part 400 may be rotatedintegrally with the rotor 320. Accordingly, when the first orbitingscroll 610 and the second orbiting scroll 710 coupled to the rotaryshaft part 400 may be rotated integrally with the rotor 320.

A balance weight may be provided on both sides in the length directionof the rotor 320, that is, on the front surface or the rear surface inthe shown embodiment. The balance weight may be configured to compensatefor the center of gravity moved when the first orbiting scroll 610 andthe second orbiting scroll 710 are eccentrically rotated.

In the shown embodiment, the balance weight is shown as being providedon the front side of the rotor 320. However, the balance weight may alsobe provided on the rear side of the rotor 320.

The rotary shaft part 400 may deliver a rotational force generated bythe motor part 300 to the compression part 600 and the expansion part700.

The rotary shaft part 400 may be installed through and coupled to themotor part 300. In this case, the rotary shaft part 400 may beintegrally rotatably coupled to the motor part 300.

The first orbiting scroll 610 of the compression part 600 may be coupledto one side of the rotary shaft part 400, that is, to the front side inthe shown embodiment. When the rotary shaft part 400 is rotated, thefirst orbiting scroll 610 may be rotated integrally with the rotaryshaft part 400.

The second orbiting scroll 710 of the expansion part 700 may be coupledto the other side of the rotary shaft part 400, that is, to the rearside in the shown embodiment. When the rotary shaft part 400 is rotated,the second orbiting scroll 710 may be rotated integrally with the rotaryshaft part 400.

The rotary shaft part 400 may be disposed to have the same central axisas the motor part 300.

The rotary shaft part 400 may serve to support the rotor 320. That is,while the rotary shaft part 400 is inserted through and coupled to therotor 320, one side in the length direction and the other side oppositeto the one side may be rotatably coupled to a first bearing unit 513 anda second bearing unit 523, respectively.

The rotary shaft part 400 may comprise a first end 410, a second end420, a pin insertion part, a pin 440, and a refrigerant communicationflow path 450.

The first end 410 may be defined as one side of the rotary shaft part400 facing the compression part 600. The first end 410 may be rotatablycoupled to the first bearing unit 513 of the first main frame 510. Inother words, the first end 410 may be rotatably supported by the firstbearing unit 513.

Thus, the rotary shaft part 400 may be rotated relative to the firstbearing unit 513.

A first balance weight 810 of the refrigerant flow adjustment part 800may be coupled to the first end 410. In detail, the first end 410 may beinserted into and coupled to a first insertion part 813 of the firstbalance weight 810.

The second end 420 may be defined as the other side of the rotary shaftpart 400 facing the expansion part 700. The second end is opposite tothe first end 410. The second end 420 may be rotatably coupled to thesecond bearing unit 523 of the second main frame 520. In other words,the second end 420 may be rotatably supported by the second bearing unit523.

Accordingly, the rotary shaft part 400 may be rotated relative to thesecond bearing unit 523.

A second balance weight 820 of the refrigerant flow adjustment part 800may be coupled to the second end 420. In detail, the second end 420 maybe inserted into and coupled to a second insertion part 823 of thesecond balance weight 820.

The pin insertion part 430 may be a space into which pins 440 a and 440b for fastening the balance weights 810 and 820 to the ends 410 and 420are to be inserted. The pin insertion part 430 may be locatedeccentrically with respect to the central axis of the rotary shaft part400.

The pin insertion part 430 may comprise a first pin insertion part 430 aand a second pin insertion part 430 b.

The first pin insertion part 430 a may be formed on the first end 410.In detail, the first pin insertion part 430 a may be recessed apredetermined distance from an end surface of the first end 410. Theshape and recessed distance of the first pin insertion part 430 a may bedetermined according to the shape and length of the first pin 440 a.

The second pin insertion part 430 b may be formed on the second end 420.In detail, the second pin insertion part 430 b may be recessed apredetermined distance from an end surface of the second end 420. Theshape and recessed distance of the second pin insertion part 430 b maybe determined according to the shape and length of the second pin 440 b.

The central axes of the pin insertion parts 430 a and 430 b may belocated eccentrically with respect to the central axis of the rotaryshaft part 400. That is, the pin insertion parts 430 a and 430 b may bedisposed to have a central axis different from that of the rotary shaftpart 400.

Thus, when the rotary shaft part 400 is rotated, the first orbitingscroll 610 and the second orbiting scroll 710 may be rotatedeccentrically with respect to the central axis of the rotary shaft part400.

The pin 440 may fasten the ends 410 and 420 to the balance weights 810and 820, respectively. The pin 440 may comprise the first pin 440 a andthe second pin 440 b.

The first pin 440 a may couple the first end 410 to the first balanceweight 810. In detail, the first pin 440 a may be inserted through andcoupled to a first pin coupling part 815 of the first balance weight 810and may be inserted into and coupled to the first pin insertion part 430a of the first end 410.

Likewise, the second pin 440 b may couple the second end 420 to thesecond balance weight 820. In detail, the second pin 440 b may beinserted through and coupled to a second pin coupling part 825 of thesecond balance weight 820 and may be inserted into and coupled to thesecond pin insertion part 430 b of the second end 420.

Accordingly, the rotary shaft part 400, the first balance weight 810,and the second balance weight 820 may be integrally rotated. Also, thebalance weights 810 and 820 coupled by the pins 440 a and 440 b may bebrought into contact with the end surfaces of the ends 410 and 420.

The first balance weight 810 coupled to the first end 410 by the firstpin 440 a may be rotatably coupled to a compression bearing 530 of theframe part 500. Also, the second balance weight 820 coupled to thesecond end 420 by the second pin 440 b may be rotatably coupled to anexpansion bearing 540 of the frame part 500.

The electric compression and expansion apparatus 10 according to anembodiment of the present disclosure may use the second balance weight820 to control a flow of refrigerant.

In the above embodiment, the second insertion part 823 of the secondbalance weight 820 may be formed not as a through-hole but as a kind ofblind hole, which may be recessed by a predetermined distance. Thesecond pin 440 b may be inserted into and coupled to the second pincoupling part 825. That is, the second pin 440 b may not be exposed tothe outside.

Also, in the above embodiment, the refrigerant communication flow path450 formed in the rotary shaft part 400 may be open or closed by themovement of the second balance weight 820. This will be described indetail below.

The refrigerant communication flow path 450 may enable a first backpressure chamber 511 of the first main frame 510 to communicate with asecond back pressure chamber 521 of the second main frame 520.Refrigerant may flow through the refrigerant communication flow path450. Refrigerant staying in the first back pressure chamber 511 may flowinto the second back pressure chamber 521 through the refrigerantcommunication flow path 450.

The refrigerant communication flow path may be formed as a through-holein the length direction of the rotary shaft part 400. In the shownembodiment, the refrigerant communication flow path 450 may be spaced apredetermined distance from the central axis of the rotary shaft part400. The refrigerant communication flow path 450 may be formed at anylocation capable of communicating with a first communication part 816 ora second communication part 826.

One side in the length direction of the refrigerant communication flowpath 450 facing the compression part 600, that is, the front side in theshown embodiment may communicate with the first back pressure chamber511. Also, the other side in the length direction of the refrigerantcommunication flow path 450 facing the expansion part 700, that is, therear side in the shown embodiment may communicate with the second backpressure chamber 521.

As a result, the refrigerant communication flow path 450, the first backpressure chamber 511, and the second back pressure chamber 521 may beconfigured to communicate with one another.

According to an embodiment of the present disclosure, a check valve 830of the refrigerant flow adjustment part 800 may be provided in therefrigerant communication flow path 450. The check valve 830 may controla flow of refrigerant in the refrigerant communication flow path 450 tobe directed from the first back pressure chamber 511 to the second backpressure chamber 521.

According to another embodiment of the present disclosure, it may bedetermined by the second balance weight 820 whether the refrigerantcommunication flow path 450 communicates with the second back pressurechamber 521.

In the above embodiment, a process of controlling communication betweenthe refrigerant communication flow path 450 and the first back pressurechamber 511 and the second back pressure chamber 521 will be describedin detail below.

The frame part 500 may be located between the main housing 100 and thecompression part 600 and between the main housing 100 and the expansionpart 700. The frame part 500 may communicate with the compression part600 and the expansion part 700.

The frame part 500 may communicate with the main housing 100 and thecompression part 600. Accordingly, refrigerant introduced into the mainhousing may be moved to the compression part 600 through the frame part500.

The frame part 500 may be configured to enable the main housing 100 andthe expansion part 700 to or not to communicate with each other. In anembodiment in which the main housing and the expansion part 700communicate with each other, a sealing member (not shown) may beprovided at a location where the frame part 500 is coupled to the mainhousing 100.

Also, the frame part 500 may rotatably support the rotary shaft part400. This can be achieved by the first bearing unit 513 and the secondbearing unit 523.

The frame part 500 may comprise the first main frame 510, the secondmain frame 520, the compression bearing 530, and the expansion bearing540.

The first main frame 510 may be located on one side of the main housing100 facing the compression part 600, that is, on the front side in theshown embodiment. The first main frame 510 may be communicativelycoupled to the main housing 100.

The compression part 600 may be located on one side of the first mainframe 510 opposite to the main housing 100, that is, on the front sidein the shown embodiment. The first main frame 510 and the compressionpart 600 may be communicatively coupled to each other.

That is, the first main frame 510 may communicate with the main housing100 and the compression part 600. As a result, the main housing 100, thecompression part 600, and the first main frame may communicate with oneanother.

In the shown embodiment, the first main frame 510 may have a circularcross-section and may have a cylindrical shape extending lengthwise,that is, in the front-rear direction. Also, the first main frame 510 maybe formed to have the same outer diameter as those of the main housing100 and the first fixed scroll 620. Accordingly, the outercircumferential surfaces of the main housing 100, the first main frame510, and the first fixed scroll 620 may be coplanar.

The first main frame 510 may comprise a first back pressure chamber 511,a first fence part 512, and a first bearing unit 513.

The first back pressure chamber 511 may be a space into which a portionof the refrigerant compressed in the compression part 600 can beintroduced. The first back pressure chamber 511 may communicate with thecompression part 600. In detail, the first back pressure chamber 511 maycommunicate with a first refrigerant intake port 613 of the firstorbiting scroll 610.

The first back pressure chamber 511 may be formed inside the first mainframe 510 by a space adjacent to the rotary shaft part 400. The firstback pressure chamber 511 may be defined as a space surrounded by therotary shaft part 400, the first fence part 512, and the compressionpart 600.

The refrigerant introduced into the first back pressure chamber 511 mayapply back pressure to the first orbiting scroll 610. That is, therefrigerant introduced into the first back pressure chamber 511 mayapply pressure to the first orbiting scroll 610 in a direction towardthe first fixed scroll 620.

As the compression of the refrigerant proceeds in the compression part600, the first orbiting scroll 610 may be pushed by the pressure of thecompressed refrigerant in a direction opposite to the first fixed scroll620.

In this case, an end surface of a first orbiting wrap 612 of the firstorbiting scroll 610 may be spaced apart from a first fixed end platepart 621 of the first fixed scroll 620. Also, a first orbiting end platepart 611 of the first orbiting scroll 610 may be spaced apart from anend surface of a first fixed wrap 622 of the first fixed scroll 620.

In this state, the refrigerant introduced into the compression part 600may be leaked into a space formed by the first orbiting scroll 610 andthe first fixed scroll 620 spaced apart from each other. As a result, itmay be difficult to reach a desired pressure even when the refrigerantis compressed.

Thus, the compressed refrigerant housed in the first back pressurechamber 511 may apply pressure to the first orbiting scroll 610 in adirection toward the first fixed scroll 620. Accordingly, the firstorbiting scroll 610 may remain in contact with the first fixed scroll620, and thus the refrigerant may be effectively compressed withoutleaking.

The first back pressure chamber 511 may communicate with the refrigerantcommunication flow path 450 of the rotary shaft part 400. In detail, thefirst back pressure chamber 511 may communicate with the refrigerantcommunication flow path 450 by means of a first communication part 816formed in the first balance weight 810. The compressed refrigerantstaying in the first back pressure chamber 511 may be introduced intothe second back pressure chamber 521 through the first communicationpart 816 and the refrigerant communication flow path 450.

The first fence part 512 may be formed inside the first main frame 510.The first fence part 512 may partition the first back pressure chamber511. In detail, the first back pressure chamber 511 may be defined by aspace surrounded by the first fence part 512. The first fence part 512may be formed as a partition.

The first fence part 512 may be brought into contact with thecompression part 600. In detail, the first fence part 512 may be broughtinto contact with the first orbiting end plate part 611 of the firstorbiting scroll 610. In the relationship with the compression part 600,the first fence part 512 may be configured to seal the first backpressure chamber 511 except for the first refrigerant intake port 613.

Therefore, the compressed refrigerant may be introduced into the firstback pressure chamber 511 through only the first refrigerant intake port613 formed in the first orbiting scroll 610.

The first fence part 512 may be spaced a predetermined distance from therotary shaft part 400 and configured to surround the outer circumferenceof the rotary shaft part 400. In the relationship with the rotary shaftpart 400, the first fence part 512 may be configured to seal the firstback pressure chamber 511 except for the first communication part 816 ofthe first balance weight 810.

Therefore, the compression part 600, the first fence part 512, and therefrigerant communication flow path 450 may communicate with one anotherby only the first refrigerant intake port 613 and the firstcommunication part 816.

The first bearing unit 513 may be provided at a portion where the firstfence part 512 and the rotary shaft part 400 can be brought into contactwith each other. Although the rotary shaft part 400 may be rotated, thefirst fence part 512 may not be rotated by the first bearing unit 513.

The first bearing unit 513 may prevent the first fence part 512 frombeing rotated regardless of the rotation of the rotary shaft part 400.The first bearing unit 513 may be located at a portion where the rotaryshaft part 400 and the first fence part 512 may be in contact with eachother, that is, at the first end 410.

The first bearing unit 513 may be provided as any member capable ofpreventing any one of two or more different elements from being rotatedregardless of the rotation of the other elements. In an embodiment, thefirst bearing unit 513 may be provided as a ball bearing.

The first bearing unit 513 may rotatably support the rotary shaft part400. The rotary shaft part 400 may be installed through and coupled tothe first bearing unit 513. The inner circumferential surface of thefirst bearing unit 513 may be brought into contact with the outercircumferential surface of the first end 410 of the rotary shaft part400. The outer circumferential surface of the first bearing unit 513 maybe brought into contact with the first fence part 512.

The first bearing unit 513 may be configured to block communicationbetween the first back pressure chamber 511 and another space of thefirst main frame 510.

The second main frame 520 may be located on the other side of the mainhousing 100 facing the expansion part 700, that is, on the rear side inthe shown embodiment. The second main frame 520 may be coupled to themain housing 100 in a communicative manner or in a non-communicativemanner.

In an embodiment in which the second main frame 520 does not communicatewith the main housing 100, a sealing member for preventing communicationof refrigerant may be provided at a portion where the second main frame520 and the main housing 100 are coupled to each other.

The expansion part 700 may be located on one side of the second mainframe 520 opposite to the main housing 100, that is, on the rear side inthe shown embodiment. The second main frame 520 and the expansion part700 may be communicatively coupled to each other.

In the shown embodiment, the second main frame 520 may have a circularcross-section and may have a cylindrical shape extending lengthwise,that is, in the front-rear direction. Also, the second main frame 520may be formed to have the same outer diameter as those of the mainhousing 100 and a second fixed scroll 720. Accordingly, the outercircumferential surfaces of the main housing 100, the second main frame520, and the second fixed scroll 720 may be coplanar.

The second main frame 520 may comprise a second back pressure chamber521, a second fence part 522, and a second bearing unit 523.

The second back pressure chamber 521 may be a space into which a portionof the refrigerant introduced into and expanded in the expansion part700 can be introduced. The second back pressure chamber 521 maycommunicate with the expansion part 700. In detail, the second backpressure chamber 521 may communicate with a second refrigerant intakeport 713 of the second orbiting scroll 710.

The second back pressure chamber 521 may be formed inside the secondmain frame 520 by a space adjacent to the rotary shaft part 400. Thesecond back pressure chamber 521 may be defined as a space surrounded bythe rotary shaft part 400, the second fence part 522, and the expansionpart 700.

The refrigerant introduced into the second back pressure chamber 521 mayapply back pressure to the second orbiting scroll 710. That is, therefrigerant introduced into the second back pressure chamber 521 mayapply pressure to the second orbiting scroll 710 in a direction towardthe second fixed scroll 720.

When the compressed refrigerant is introduced into the expansion part700, the second orbiting scroll 710 may be pushed by the pressure of thecompressed refrigerant in a direction opposite to the second fixedscroll 720.

In this case, an end surface of a second orbiting wrap 712 of the secondorbiting scroll 710 may be spaced apart from a second fixed end platepart 721 of the second fixed scroll 720. Likewise, a second orbiting endplate part 711 of the second orbiting scroll 710 may be spaced apartfrom an end surface of a second fixed wrap 722 of the second fixedscroll 720.

In this state, the refrigerant introduced into the expansion part 700may be leaked into a space formed by the second orbiting scroll 710 andthe second fixed scroll 720 spaced apart from each other. As a result,any element housed in the second main frame 520 and the expansion part700 may be damaged by high-pressure refrigerant.

Also, the refrigerant may be discharged to the outside of the electriccompression and expansion apparatus 10 without being sufficientlyexpanded. As a result, the efficiency of the air conditioning system 1may be reduced, and also other devices included in the air conditioningsystem 1 may be damaged.

Thus, the expanded refrigerant housed in the second back pressurechamber 521 may apply pressure to the second orbiting scroll 710 in adirection toward the second fixed scroll 720. Accordingly, the secondorbiting scroll 710 may remain in contact with the second fixed scroll720, and thus the refrigerant may be effectively expanded withoutleaking.

The second back pressure chamber 521 may communicate with therefrigerant communication flow path 450 of the rotary shaft part 400. Indetail, the second back pressure chamber 521 may communicate with therefrigerant communication flow path 450 by means of a secondcommunication part 826 formed in the second balance weight 820.Accordingly, the compressed refrigerant staying in the first backpressure chamber 511 may be introduced into the second back pressurechamber 521 through the refrigerant communication flow path 450 and thesecond communication part 826.

The electric compression and expansion apparatus 10 according to anembodiment of the present disclosure may be configured such that therefrigerant staying in the first back pressure chamber 511 may be movedto the second back pressure chamber 521 while the refrigerant staying inthe second back pressure chamber 521 is not moved to the first backpressure chamber 511. This will be described in detail below.

The second fence part 522 may be formed inside the second main frame520. The second fence part 522 may partition the second back pressurechamber 521. In detail, the second back pressure chamber 521 may bedefined by a space surrounded by the second fence part 522. The secondfence part 522 may be formed as a partition.

The second fence part 522 may be brought into contact with the expansionpart 700. In detail, the second fence part 522 may be brought intocontact with the second orbiting end plate part 711 of the secondorbiting scroll 710. In the relationship with the expansion part 700,the second fence part 522 may be configured to seal the second backpressure chamber 521 except for the second refrigerant intake port 713.

Therefore, the expanded refrigerant may be introduced into the secondback pressure chamber 521 through only the second refrigerant intakeport 713 formed in the second orbiting scroll 710.

The second fence part 522 may be spaced a predetermined distance fromthe rotary shaft part 400 and configured to surround the outercircumference of the rotary shaft part 400. In the relationship with therotary shaft part 400, the second fence part 522 may be configured toseal the second back pressure chamber 521 except for the secondcommunication part 826 of the second balance weight 820.

Also, in another embodiment in which the second balance weight 820 ismoved to open or close the refrigerant communication flow path 450, thesecond fence part 522 may be configured to seal the second back pressurechamber 521 except for the refrigerant communication flow path 450.

The second bearing unit 523 may be provided at a portion where thesecond fence part 522 and the rotary shaft part 400 are brought intocontact with each other. Although the rotary shaft part 400 may berotated, the second fence part 522 may not be rotated by the secondbearing unit 523.

The second bearing unit 523 may prevent the second fence part 522 frombeing rotated regardless of the rotation of the rotary shaft part 400.The second bearing unit 523 may be located at a portion where the rotaryshaft part 400 and the second fence part 522 are in contact with eachother, that is, at the second end 420.

The second bearing unit 523 may be provided as any member capable ofpreventing any one of two or more different elements from being rotatedregardless of the rotation of the other elements. In an embodiment, thesecond bearing unit 523 may be provided as a ball bearing.

The second bearing unit 523 may rotatably support the rotary shaft part400. The rotary shaft part 400 may be installed through and coupled tothe second bearing unit 523. The inner circumferential surface of thesecond bearing unit 523 may be brought into contact with the outercircumferential surface of the second end 420 of the rotary shaft part400. The outer circumferential surface of the second bearing unit 523may be brought into contact with the second fence part 522.

The second bearing unit 523 may be configured to block communicationbetween the main housing 100 and the second back pressure chamber 521.In this case, a sealing member may be provided between the secondbearing unit 523 and the second main frame 520.

Alternatively, the second bearing unit 523 may be configured to enablethe main housing 100 and the second back pressure chamber 521 tocommunicate with each other. In this case, a predetermined space forcommunication of refrigerant may be formed between the second bearingunit 523 and the second fence part 522.

The compression bearing 530 may rotatably support the first balanceweight 810 inserted into and coupled to the first pin 440 a. Thecompression bearing 530 may be located in contact with the firstorbiting scroll 610.

In detail, the outer circumferential surface of the compression bearing530 may be located in contact with the inner circumferential surface ofa compression bearing coupling part 614 protruding from one surface ofthe first orbiting end plate part 611 opposite to the first orbitingwrap 612. The compression bearing 530 may be fixed and coupled to thefirst orbiting scroll 610.

The outer circumferential surface of the first protrusion part 812 ofthe first balance weight 810 may be brought into contact with the innercircumferential surface of the compression bearing 530. When the firstbalance weight 810 is rotated along with the rotation of the rotaryshaft part 400, the first orbiting scroll 610 may be rotated togetherwith the rotary shaft part 400.

The expansion bearing 540 may rotatably support the second balanceweight 820 inserted into and coupled to the second pin 440 b. Theexpansion bearing 540 may be located in contact with the second orbitingscroll 710.

In detail, the outer circumferential surface of the expansion bearing540 may be located in contact with the inner circumferential surface ofan expansion bearing coupling part 714 protruding from one surface ofthe second orbiting end plate part 711 opposite to the second orbitingwrap 712. The expansion bearing 540 may be fixed and coupled to thesecond orbiting scroll 710.

The outer circumferential surface of the second protrusion part 822 ofthe second balance weight 820 may be brought into contact with the innercircumferential surface of the expansion bearing 540. When the secondbalance weight 820 is rotated along with the rotation of the rotaryshaft part 400, the second orbiting scroll 710 may be rotated togetherwith the rotary shaft part 400.

The compression part 600 may be rotated by a rotational force generatedby the motor part 300 to substantially serve to compress refrigerant.The compression part 600 may be connected to the motor part 300 by therotary shaft part 400. The compression part 600 may be rotatedintegrally with the motor part 300 and the rotary shaft part 400.

The compression part 600 may be located on one side of the first mainframe 510 opposite to the main housing 100, that is, on the front sidein the shown embodiment. The rear housing 200 may be located on one sideof the compression part 600 opposite to the first main frame 510, thatis, on the front side in the shown embodiment.

The compression part 600 may be communicatively coupled to the rearhousing 200. Also, the compression part 600 may be communicativelycoupled to the first main frame 510. Thus, the compression part 600, therear housing 200, and the first main frame 510 may be communicativelycoupled to one another.

The compression part 600 may comprise the first orbiting scroll 610 andthe first fixed scroll 620.

The first orbiting scroll 610 may be configured to orbit along with therotation of the motor part 300. The first orbiting scroll 610 may becoupled to the rotary shaft part 400. In detail, the first orbitingscroll 610 may be coupled to the first balance weight 810 coupled to therotary shaft part 400 by the first pin 440 a. When the first balanceweight 810 is rotated, the first orbiting scroll 610 may also berotated.

Accordingly, when the rotary shaft part 400 is rotated, the firstorbiting scroll 610 may be rotated.

The rotational axis of the first orbiting scroll 610 may be eccentricwith respect to the central axis of the rotary shaft part 400. That is,the first pin insertion part 430 a into which the first pin 440 a isinserted may be formed eccentrically with respect to the central axis ofthe rotary shaft part 400. Thus, the rotational axis of the firstorbiting scroll 610 may be eccentric with respect to the central axis ofthe rotary shaft part 400.

On the contrary, the first fixed scroll 620 may be configured to havethe same central axis as the rotary shaft part 400. That is, the firstorbiting scroll 610 may be rotated eccentrically with respect to eventhe first fixed scroll 620.

By the eccentric rotation of the first orbiting scroll 610, refrigerantmay be compressed in a space between the first orbiting wrap 612 and thefirst fixed wrap 622.

One side of the first orbiting scroll 610 adjacent to the first mainframe 510, that is, the rear side in the shown embodiment may berotatably coupled to the first main frame 510. In detail, the rear sideof the first orbiting scroll 610 may be brought into contact with thefirst fence part 512 of the first main frame 510.

Accordingly, the first back pressure chamber 511 may be formed betweenthe first orbiting scroll 610 and the first fence part 512.

The compression bearing coupling part 614 for supporting the compressionbearing 530 may be formed to protrude from one side of the firstorbiting scroll 610 adjacent to the first main frame 510, that is, fromthe rear side in the shown embodiment. The inner circumferential surfaceof the compression bearing coupling part 614 may be brought into contactwith the outer circumferential surface of the compression bearing 530.

The diameter of the first orbiting scroll 610 may be smaller than thediameter of the first fixed scroll 620. Accordingly, the first orbitingscroll 610 may be fully housed in the first fixed scroll 620.

The first orbiting scroll 610 may comprise the first orbiting end platepart 611, the first orbiting wrap 612, the first refrigerant intake port613, and the compression bearing coupling part 614.

The first orbiting end plate part 611 may form the body of the firstorbiting scroll 610. In the shown embodiment, the first orbiting endplate part 611 may be located adjacent to the first main frame 510.

One surface of the first orbiting end plate part 611 facing the firstmain frame 510, that is, the rear surface in the shown embodiment may bebrought into contact with the first fence part 512 of the first mainframe 510. Also, the other surface of the first orbiting end plate part611 opposite to the one surface, that is, the front surface in the shownembodiment may be brought into contact with an end surface of the firstfixed wrap 622 of the first fixed scroll 620.

The first orbiting wrap 612 may be coupled to the first fixed wrap 622of the first fixed scroll 620 with a predetermined space formedtherebetween. In an embodiment, the first orbiting wrap 612 may becoupled to the first fixed wrap 622 such that the first orbiting wrap612 and the first fixed wrap 622 are spaced a predetermined distancefrom and engaged with each other.

While the first orbiting wrap 612 is coupled to the first fixed wrap622, the first orbiting scroll 610 may be rotated eccentrically withrespect to the rotary shaft part 400. Accordingly, refrigerant may becompressed in a space between the first orbiting wrap 612 and the firstfixed wrap 622.

The first orbiting wrap 612 may be formed to protrude from the firstorbiting end plate part 611. In detail, the first orbiting wrap 612 maybe formed to protrude toward one side of the first orbiting end platepart 611 facing the rear housing 200, that is, from the front side inthe shown embodiment.

The first orbiting wrap 612 may be spirally formed. The first fixed wrap622 may also be spirally formed. When the first orbiting wrap 612 andthe first fixed wrap 622 are coupled to each other, a predeterminedspace for compressing refrigerant may be formed therebetween.

The first refrigerant intake port 613 may be a passage through which therefrigerant compressed in the space between the first orbiting wrap 612and the first fixed wrap 622 (hereinafter referred to as a compressionspace C.S) can be introduced into the first back pressure chamber 511.The first refrigerant intake port 613 may enable the compression spaceC.S to communicate with the first back pressure chamber 511.

The first refrigerant intake port 613 may be formed through the firstorbiting end plate part 611. A portion of the refrigerant compressed inthe compression space C.S may be introduced into the first back pressurechamber 511 through the first refrigerant intake port 613.

The compression bearing coupling part 614 rotatably supports thecompression bearing 530. The compression bearing coupling part 614 maybe formed in a donut shape having a hollow portion formed therein.

The compression bearing coupling part 614 may be formed to protrude fromone side of the first orbiting end plate part 611 facing the first mainframe 510, that is, from the rear side in the shown embodiment. Theinner circumferential surface of the compression bearing coupling part614 may be in contact with the outer circumferential surface of thecompression bearing 530.

The first fixed scroll 620 may be configured to compress refrigerantalong with the relative rotation of the first orbiting scroll 610. Thefirst fixed scroll 620 may not be rotated regardless of the rotation ofthe first orbiting scroll 610.

The first fixed scroll 620 may be located between the rear housing 200and the first main frame 510. Also, the outer circumferential surface ofthe first fixed scroll 620 may be exposed to the outside. In anotherembodiment, the first fixed scroll 620 may be housed in the first mainframe 510 or the main housing 100.

The first fixed scroll 620 may have a circular cross-section and has acylindrical shape extending lengthwise. The outer circumferentialsurface of the first fixed scroll 620 may be coplanar with the outercircumferential surfaces of the first main frame 510 and the rearhousing 200.

The first fixed scroll 620 may communicate with the first main frame510. Also, the first fixed scroll 620 may communicate with the dischargechamber 230 of the rear housing 200.

The first fixed scroll 620 may comprise the first fixed end plate part621, the first fixed wrap 622, a discharge valve 623, and a dischargeport 624.

The first fixed end plate part 621 may form the body of the first fixedscroll 620. In the shown embodiment, the first fixed end plate part 621may be located adjacent to the rear housing 200.

One surface of the first fixed end plate part 621 facing the rearhousing 200, that is, the front surface in the shown embodiment may forma predetermined space and may be brought into contact with one surfaceof the rear housing 200. The discharge chamber 230 may be defined by thespace.

Also, the other surface of the first fixed end plate part 621 oppositeto the one surface, that is, the rear surface in the shown embodimentmay be brought into contact with an end surface of the first orbitingwrap 612 of the first orbiting scroll 610.

The first fixed wrap 622 may be coupled to the first orbiting wrap 612of the first orbiting scroll 610 with a compression space C.S formedtherebetween. While the first fixed wrap 622 and the first orbiting wrap612 are coupled to each other, the first orbiting scroll 610 may berotated eccentrically with respect to the rotary shaft part 400.Accordingly, refrigerant may be compressed in the compression space C.S.

The first fixed wrap 622 may be formed to protrude from the first fixedend plate part 621. In detail, the first fixed wrap 622 may be formed toprotrude toward one side of the first fixed end plate part 621 facingthe first orbiting scroll 610, that is, toward the rear side in theshown embodiment.

The first fixed wrap 622 may be spirally formed and may be coupled tothe first orbiting wrap 612 with the compression space C.S formedtherebetween.

The discharge valve 623 may be configured to open or close the dischargeport 624, which may be a passage through which the compressedrefrigerant can be introduced, by a relative rotation between the firstorbiting scroll 610 and the first fixed scroll 620.

The discharge valve 623 may be configured to enable the discharge port624 and the discharge chamber 230 to communicate with each other whenthe pressure of refrigerant having flowed into the discharge port 624 isgreater than or equal to a predetermined pressure. In an embodiment, thedischarge valve 623 may be provided as a check valve such as a reedvalve for restricting a flow of fluid in a specific direction dependingon the pressure.

The discharge valve 623 may be provided on one surface of the firstfixed end plate part 621 facing the rear housing 200, that is, the frontsurface in the shown embodiment. The discharge valve 623 may beconfigured to cover the discharge port 624.

The discharge port 624 may enable the compression part 600 and thedischarge chamber 230 to communicate with each other. The refrigerantcompressed in the compression part 600 may flow into the dischargechamber 230 through the discharge port 624.

The discharge port 624 may be open or closed by the discharge valve 623.When the pressure of the refrigerant having entered the discharge port624 is less than or equal to a predetermined pressure, the dischargevalve 623 may close the discharge port 624. When the pressure of therefrigerant having entered the discharge port 624 exceeds apredetermined pressure, the discharge valve 623 may open the dischargeport 624.

The compressed refrigerant having entered the discharge chamber 230through the discharge port 624 may be discharged to the outside of theelectric compression and expansion apparatus 10 through the exhaust port212 via the exhaust flow path 210.

The expansion part 700 may be rotated by a rotational force generated bythe motor part 300 to substantially serve to expand refrigerant. Theexpansion part 700 may be connected to the motor part 300 by the rotaryshaft part 400. The expansion part 700 may be rotated integrally withthe motor part 300 and the rotary shaft part 400.

The expansion part 700 may be located on one side of the second mainframe 520 opposite to the main housing 100, that is, on the rear side inthe shown embodiment.

The expansion part 700 may be communicatively coupled to the second mainframe 520. Refrigerant introduced into and expanded in the expansionpart 700 may be introduced into the second main frame 520.

The expansion part 700 may comprise the second orbiting scroll 710 andthe second fixed scroll 720.

The second orbiting scroll 710 may be configured to orbit along with therotation of the motor part 300. The second orbiting scroll 710 may becoupled to the rotary shaft part 400. In detail, the second orbitingscroll 710 may be coupled to the second balance weight 820 coupled tothe rotary shaft part 400 by the second pin 440 b. When the secondbalance weight 820 is rotated, the second orbiting scroll 710 may alsobe rotated.

Accordingly, when the rotary shaft part 400 is rotated, the secondorbiting scroll 710 may be rotated.

The central axis of the second orbiting scroll 710 may be eccentric withrespect to the central axis of the rotary shaft part 400. That is, thesecond pin insertion part 430 b into which the second pin 440 b isinserted may be formed eccentrically with respect to the central axis ofthe rotary shaft part 400. Thus, the rotational axis of the secondorbiting scroll 710 may be eccentric with respect to the central axis ofthe rotary shaft part 400.

On the contrary, the second fixed scroll 720 may be configured to havethe same central axis as the rotary shaft part 400. That is, the secondorbiting scroll 710 may be rotated eccentrically with respect to eventhe second fixed scroll 720.

By the eccentric rotation of the second orbiting scroll 710, refrigerantmay be expanded in a space between the second orbiting wrap 712 and thesecond fixed wrap 722 (hereinafter referred to as an expansion spaceE.S).

The front surface of the second orbiting scroll 710 may be brought intocontact with the second fence part 522 of the second main frame 520.

Accordingly, the second back pressure chamber 521 may be formed betweenthe second orbiting scroll 710 and the second fence part 522.

The expansion bearing coupling part 714 for supporting the expansionbearing 540 may be formed to protrude from one side of the secondorbiting scroll 710 adjacent to the second main frame 520, that is, fromthe front side in the shown embodiment. The inner circumferentialsurface of the expansion bearing coupling part 714 may be brought intocontact with the outer circumferential surface of the expansion bearing540.

The diameter of the second orbiting scroll 710 may be smaller than thediameter of the second fixed scroll 720. Accordingly, the secondorbiting scroll 710 may be fully housed in the second fixed scroll 720.

The second orbiting scroll 710 may comprise the second orbiting endplate part 711, the second orbiting wrap 712, the second refrigerantintake port 713, and the expansion bearing coupling part 714.

The second orbiting end plate part 711 may form the body of the secondorbiting scroll 710. In the shown embodiment, the second orbiting endplate part 711 may be located adjacent to the second main frame 520.

One surface of the second orbiting end plate part 711 facing the secondmain frame 520, that is, the front surface in the shown embodiment maybe brought into contact with the second fence part 522 of the secondmain frame 520. Also, the other surface of the second orbiting end platepart 711 opposite to the one surface, that is, the rear surface in theshown embodiment may be brought into contact with an end surface of thesecond fixed wrap 722 of the second fixed scroll 720.

The second orbiting wrap 712 may be coupled to the second fixed wrap 722of the second fixed scroll 720 with a predetermined space formedtherebetween. In an embodiment, the second orbiting wrap 712 may becoupled to the second fixed wrap 722 such that the second orbiting wrap712 and the second fixed wrap 722 are spaced a predetermined distancefrom and engaged with each other.

While the second orbiting wrap 712 is coupled to the second fixed wrap722, the second orbiting scroll 710 may be rotated eccentrically withrespect to the rotary shaft part 400. Accordingly, refrigerant may beexpanded in the expansion space E.S between the second orbiting wrap 712and the second fixed wrap 722.

The second orbiting wrap 712 may be formed to protrude from the secondorbiting end plate part 711. In detail, the second orbiting wrap 712 maybe formed to protrude toward one side of the second orbiting end platepart 711 facing the second fixed scroll 720, that is, toward the rearsurface in the shown embodiment.

The second orbiting wrap 712 may be spirally formed. The second fixedwrap 722 may also be spirally formed. When the second orbiting wrap 712and the second fixed wrap 722 are coupled to each other, the expansionspace E.S may be formed therebetween.

The second refrigerant intake port 713 may be a passage through whichthe refrigerant expanded in the expansion space E.S can be introducedinto the second back pressure chamber 521. The second refrigerant intakeport 713 may enable the expansion space E.S to communicate with thesecond back pressure chamber 521.

The second refrigerant intake port 713 may be formed through the secondorbiting end plate part 711. A portion of the refrigerant expanded inthe expansion space E.S may be introduced into the second back pressurechamber 521 through the second refrigerant intake port 713.

The expansion bearing coupling part 714 may rotatably support theexpansion bearing 540. The expansion bearing coupling part 714 may beformed in a donut shape having a hollow portion formed therein.

The expansion bearing coupling part 714 may be formed to protrude fromone side of the second orbiting end plate part 711 facing the secondmain frame 520, that is, from the front side in the shown embodiment.The inner circumferential surface of the expansion bearing coupling part714 may be brought into contact with the outer circumferential surfaceof the expansion bearing 540.

The second fixed scroll 720 may be located behind the second orbitingscroll 710 and the second main frame 520. Also, the outer surface of thesecond fixed scroll 720 may be exposed to the outside. In anotherembodiment, the second fixed scroll 720 may be housed in the second mainframe 520 or the main housing 100.

The second fixed scroll 720 may have a circular cross-section and has acylindrical shape extending lengthwise. The outer circumferentialsurface of the second fixed scroll 720 may be coplanar with the outercircumferential surfaces of the second main frame 520 and the mainhousing 100.

The second fixed scroll 720 may communicate with the second main frame520. Also, in an embodiment, the second fixed scroll 720 may beconfigured to communicate with even the main housing 100.

The second fixed scroll 720 may comprise the second fixed end plate part721, the second fixed wrap 722, an outer surface 723, a refrigerantintake opening 724, a discharge chamber 725, and a refrigerant dischargeopening 726.

The second fixed end plate part 721 may form the body of the secondfixed scroll 720. In the shown embodiment, the second fixed end platepart 721 may form the rear side of the second fixed scroll 720. The endsurface of the second orbiting wrap 712 may be brought into contact withthe one surface of the second fixed end plate part 721.

The second fixed wrap 722 may be coupled to the second orbiting wrap 712of the second orbiting scroll 710 with the expansion space E.S formedtherebetween. While the second fixed wrap 722 and the second orbitingwrap 712 are coupled to each other, the second orbiting scroll 710 maybe rotated eccentrically with respect to the rotary shaft part 400.Accordingly, refrigerant may be expanded in the expansion space E.S.

The second fixed wrap 722 may be formed to protrude from the secondfixed end plate part 721. In detail, the second fixed wrap 722 may beformed to protrude toward one side of the second fixed end plate part721 facing the second orbiting scroll 710, that is, toward the frontside in the shown embodiment.

The second fixed wrap 722 may be spirally formed and may be coupled tothe second orbiting wrap 712 with the expansion space E.S formedtherebetween.

The outer surface 723 may be a planar surface where the second fixedscroll 720 is exposed to the outside. The outer surface 723 may bedefined as one surface of the second fixed scroll 720 opposite to thesecond orbiting scroll 710. In the shown embodiment, the outer surface723 may be the rear surface of the second fixed scroll 720.

The refrigerant intake opening 724 may be formed through the outersurface 723.

The refrigerant intake opening 724 may be a passage through which thecompressed refrigerant can be introduced into the expansion part 700.The refrigerant intake opening 724 may be formed through the outersurface 723 and configured to enable the inside and outside of theexpansion part 700 to communicate with each other.

In the shown embodiment, the refrigerant intake opening 724 may beformed at a center portion of the outer surface 723. This may be toprevent the rotation of the second orbiting scroll 710 from beingaffected by the introduction of the refrigerant.

The refrigerant introduced into the refrigerant intake opening 724 maybe expanded via the expansion space E.S and may flow into the secondback pressure chamber 521 or the discharge chamber 725.

The discharge chamber 725 may be a space where the expanded refrigerantstays before being discharged. The discharge chamber 725 may be definedas a space formed inside the second fixed scroll 720.

The discharge chamber 725 may communicate with the expansion space E.S.Also, the discharge chamber 725 may communicate with the refrigerantdischarge opening 726. The refrigerant expanded in the expansion spaceE.S may flow to the refrigerant discharge opening 726 via the dischargechamber 725.

The refrigerant discharge opening 726 may form a flow path through theexpanded refrigerant can be discharged. The refrigerant dischargeopening 726 may communicate with the discharge chamber 725. Also, therefrigerant discharge opening 726 may communicate with the outside ofthe electric compression and expansion apparatus 10.

The expanded refrigerant staying in the discharge chamber 725 may bedischarged to the outside of the electric compression and expansionapparatus 10 through the refrigerant discharge opening 726.

The refrigerant flow adjustment part 800 may be configured to adjust theflow of the refrigerant between the compression part 600 and theexpansion part 700. In detail, the refrigerant flow adjustment part 800may adjust communication between the first back pressure chamber 511 andthe second back pressure chamber 521 and may adjust the flow of therefrigerant staying in the back pressure chambers 511 and 521.

As described above, the refrigerant may be adjusted to flow in only adirection from the first back pressure chamber 511 to the second backpressure chamber 521. To this end, the refrigerant flow adjustment part800 may comprise members for forming or blocking the communicationbetween the first back pressure chamber 511 and the second back pressurechamber 521.

The refrigerant flow adjustment part 800 may comprise the first balanceweight 810, the second balance weight 820, and the check valve 830.

The first balance weight 810 may be coupled to the first end 410 of therotary shaft part 400. The first balance weight 810 may be configured toresolve an imbalance caused by the rotation of the first orbiting scroll610.

In detail, the first orbiting scroll 610 may be rotated eccentricallywith respect to the rotary shaft part 400. This may result in animbalance of mass and thus an imbalance of moment.

The first balance weight 810 may resolve an imbalance caused by theeccentric rotation of the first orbiting scroll 610. To this end, thefirst balance weight 810 may be formed to have an asymmetric mass withrespect to the central axis of the rotary shaft part 400.

Further referring to FIGS. 5A and 5B, the first balance weight 810 maycomprise a first body part 811, a first protrusion part 812, a firstinsertion part 813, a first eccentric part 814, a first pin couplingpart 815, and a first communication part 816.

The first body part 811 may form the body of the first balance weight810. In the shown embodiment, the first body part 811 may be provided ina disk shape, but the shape may be changeable.

When the first balance weight 810 is coupled to the first end 410 of therotary shaft part 400, one surface of the first body part 811 where thefirst insertion part 813 is formed may be brought into contact with anend surface of the first end 410.

The first protrusion part 812 may be formed to protrude from the firstbody part 811. In detail, the first protrusion part 812 may be formed toprotrude from one surface of the first body part 811 opposite to thefirst insertion part 813.

In the shown embodiment, the first protrusion part 812 may have acircular cross-section and may have a cylindrical shape extendinglengthwise. This may be to rotatably couple to the first bearing unit513 of the first main frame 510.

The first protrusion part 812 may be rotatably coupled to the firstbearing unit 513. Even though the first balance weight 810 is rotatedalong with the rotary shaft part 400, the first main frame 510 coupledto the first bearing unit 513 may not be rotated.

The first insertion part 813 may be a space where the first balanceweight 810 is coupled to the first end 410 of the rotary shaft part 400.That is, the first end 410 may be inserted into and coupled to the firstinsertion part 813.

The first insertion part 813 may be defined by one surface of the firstbody part 811 and a first inner circumferential surface 814 a of thefirst eccentric part 814. The first insertion part 813 may be formed onone side of the first body part 811 opposite to the first protrusionpart 812.

The first eccentric part 814 may substantially serve to resolve animbalance caused by the eccentric rotation of the first orbiting scroll610. That is, the first eccentric part 814 may be configured such thatthe first balance weight 810 has an asymmetric mass distribution withrespect to the rotary shaft part 400.

In the shown embodiment, the first eccentric part 814 may have a fanshape extending radially outward from the first body part 811. Also, thefirst eccentric part 814 may be formed to protrude a predetermineddistance in a direction toward the rotary shaft part 400.

Accordingly, the first eccentric part 814 may have a larger mass thanthe other portions of the first balance weight 810 in which the firsteccentric part 814 is not formed.

A portion of the first eccentric part 814 formed to protrude in thedirection toward the rotary shaft part 400 may have a closed arc shape.That is, the portion may comprise a first inner circumferential surface814 a adjacent to the first body part 811 and a first innercircumferential surface 814 b spaced apart from the first body part 811.

The first inner circumferential surface 814 a may form the innercircumference of the first insertion part 813. The first innercircumferential surface 814 b may form the outer circumference of thefirst eccentric part 814.

The shape of the first inner circumferential surface 814 a may bedetermined to correspond to the shape of the outer circumference of thefirst end 410 of the rotary shaft part 400. Accordingly, when the firstbalance weight 810 is coupled to the first end 410, the first end 410may be stably inserted into the first insertion part 813.

The first pin coupling part 815 may be a space into which the first pin440 a can be inserted. The first pin coupling part 815 may be formedlengthwise through the first body part 811 and the first protrusion part812. The shape of the first pin coupling part 815 may be determined tocorrespond to the shape of the first pin 440 a.

The first pin coupling part 815 may be disposed eccentrically withrespect to the central axis of the first body part 811 and the firstprotrusion part 812. Also, the first pin coupling part 815 may bedisposed eccentrically with respect to the central axis of the rotaryshaft part 400.

Accordingly, the first balance weight 810 coupled to the first end 410by the first pin 440 a and the first orbiting scroll 610 coupled to thefirst balance weight 810 may be rotated eccentrically with respect tothe rotary shaft part 400.

The first communication part 816 may be configured to enable the firstback pressure chamber 511 and the refrigerant communication flow path450 to communicate with each other. The first communication part 816 maybe recessed a predetermined distance from one side of the first bodypart 811, that is, from one surface facing the first insertion part 813.

In the shown embodiment, the first communication part 816 may be formedto extend from the outer circumference of the first body part 811 to thefirst pin coupling part 815. The first communication part 816 shouldjust be formed to extend such that the first back pressure chamber 511can communicate with the refrigerant communication flow path 450.

When the first balance weight 810 is coupled to the first bearing unit513 and the first end 410, the end of the first communication part 816,that is, a portion of the first communication part 816 formed on theouter circumference of the first body part may communicate with thefirst back pressure chamber 511.

Also, a portion extending radially inward from a portion of the firstcommunication part 816 adjacent to the first pin coupling part 815, thatis, a portion of the first communication part 816 communicating with thefirst back pressure chamber 511 may communicate with the refrigerantcommunication flow path 450.

Accordingly, the flow path of refrigerant may be formed along the firstback pressure chamber 511, the first communication part 816, and therefrigerant communication flow path 450.

The second balance weight 820 may be coupled to the second end 420 ofthe rotary shaft part 400. The second balance weight 820 may beconfigured to resolve an imbalance caused by the rotation of the secondorbiting scroll 710.

In detail, the second orbiting scroll 710 may be rotated eccentricallywith respect to the rotary shaft part 400, which may cause an imbalanceof mass and an imbalance of moment.

The second balance weight 820 may be formed to have an asymmetric masswith respect to the central axis of the rotary shaft part 400 and may beconfigured to solve an imbalance caused by the eccentric rotation of thesecond orbiting scroll 710.

As described below, the electric compression and expansion apparatus 10according to an embodiment of the present disclosure may be adjusted bythe check valve or the second balance weight 820 to enable therefrigerant communication flow path 450 and the second back pressurechamber 521 to or not to communicate with each other.

In an embodiment in which the flow of refrigerant is controlled by thecheck valve 830, the second balance weight 820 may have the samestructure and function as the first balance weight 810.

That is, in the embodiment shown in FIGS. 5A and 5B, the second balanceweight 820 may comprise a second body part 821, a second protrusion part822, a second insertion part 823, a second eccentric part 824, thesecond pin coupling part 825, and the second communication part 826.

The second body part 821 may form the body of the second balance weight820. In the shown embodiment, the second body part 821 may be providedin a disk shape, but the shape may be changeable.

When the second balance weight 820 may be coupled to the second end 420of the rotary shaft part 400, one surface of the second body part 821where the second insertion part 823 is formed may be brought intocontact with an end surface of the second end 420.

The second protrusion part 822 may be formed to protrude from the secondbody part 821. In detail, the second protrusion part 822 may be formedto protrude from one surface of the second body part 821 opposite to thesecond insertion part 823.

In the shown embodiment, the second protrusion part 822 may have acircular cross-section and may have a cylindrical shape extendinglengthwise. This may be to rotatably couple to the second bearing unit523 of the second main frame 520.

The second protrusion part 822 may be rotatably coupled to the secondbearing unit 523. Even though the second balance weight 820 is rotatedalong with the rotary shaft part 400, the second main frame 520 coupledto the second bearing unit 523 may not be rotated.

The second insertion part 823 may be a space where the second balanceweight 820 is coupled to the second end 420 of the rotary shaft part400. That is, the second end 420 may be inserted into and coupled to thesecond insertion part 823.

The second insertion part 823 may be defined by one surface of thesecond body part 821 and a second inner circumferential surface 824 a ofthe second eccentric part 824. The second insertion part 823 may beformed on one side of the second body part 821 opposite to the secondprotrusion part 822.

The second eccentric part 824 may substantially serve to resolve animbalance caused by the eccentric rotation of the second orbiting scroll710. That is, the second eccentric part 824 may be configured such thatthe second balance weight 820 has an asymmetric mass distribution withrespect to the rotary shaft part 400.

In the shown embodiment, the second eccentric part 824 may have a fanshape extending radially outward from the second body part 821. Also,the second eccentric part 824 may be formed to protrude a predetermineddistance in the direction toward the rotary shaft part 400.

Accordingly, the second eccentric part 824 may have a larger mass thanthe other portions of the second balance weight 820 in which the secondeccentric part 824 is not formed.

A portion of the second eccentric part 824 formed to protrude in thedirection toward the rotary shaft part 400 may have a closed arc shape.That is, the portion may comprise a second inner circumferential surface824 a adjacent to the second body part 821 and a second innercircumferential surface 824 b spaced apart from the second body part821.

The second inner circumferential surface 824 a may form the innercircumference of the second insertion part 823. The second innercircumferential surface 824 b may form the outer circumference of thesecond eccentric part 824.

The shape of the second inner circumferential surface 824 a may bedetermined to correspond to the shape of the outer circumference of thesecond end 420 of the rotary shaft part 400. Accordingly, when thesecond balance weight 820 is coupled to the second end 420, the secondend 420 may be stably inserted into the second insertion part 823.

The second pin coupling part 825 may be a space into which the secondpin 440 b is to be inserted. The second pin coupling part 825 may beformed lengthwise through the second body part 821 and the secondprotrusion part 822. The shape of the second pin coupling part 825 maybe determined to correspond to the shape of the second pin 440 b.

The second pin coupling part 825 may be disposed eccentrically withrespect to the central axis of the second body part 821 and the secondprotrusion part 822. Also, the second pin coupling part 825 may bedisposed eccentrically with respect to the central axis of the rotaryshaft part 400.

Accordingly, the second balance weight 820 coupled to the second end 420by the second pin 440 b and the second orbiting scroll 710 coupled tothe second balance weight 820 may be rotated eccentrically with respectto the rotary shaft part 400.

The second communication part 826 may be configured to enable the secondback pressure chamber 521 and the refrigerant communication flow path450 to communicate with each other. The second communication part 826may be recessed a predetermined distance from one side of the secondbody part 821, that is, from one surface facing the second insertionpart 823.

In the shown embodiment, the second communication part 826 may be formedto extend from the outer circumference of the second body part 821 tothe second pin coupling part 825. The second communication part 826 mayjust be formed to extend such that the second back pressure chamber 521can communicate with the refrigerant communication flow path 450.

When the second balance weight 820 is coupled to the second bearing unit523 and the second end 420, the end of the second communication part826, that is, a portion of the second communication part 826 formed onthe outer circumference of the second body part may communicate with thesecond back pressure chamber 521.

Also, a portion extending radially inward from a portion of the secondcommunication part 826 adjacent to the second pin coupling part 825,that is, a portion of the second communication part 826 communicatingwith the second back pressure chamber 521 may communicate with therefrigerant communication flow path 450.

Accordingly, the flow path of refrigerant may be formed along the secondback pressure chamber 521, the second communication part 826, and therefrigerant communication flow path 450.

Referring to FIGS. 6A-6B and 7A-7B again, an embodiment in which theflow of the refrigerant may be controlled by a second balance weight820′.

The second balance weight 820′ according to this embodiment may beconfigured to open or close the refrigerant communication flow path 450.Accordingly, the refrigerant communication flow path 450 may or may notcommunicate with the second back pressure chamber 521.

The following description focuses on the difference between the abovesecond balance weight 820 and the second balance weight 820′ accordingto this embodiment.

A second body part 821′, a second protrusion part 822′, a secondinsertion part 823′, and a second eccentric part 824′ of the secondbalance weight 820′ may be same as the second body part 821, the secondprotrusion part 822, the insertion part 823, and the second eccentricpart 824, which have been described above, respectively.

The second pin 440 b may be inserted into the second pin coupling part825′. The second pin coupling part 825′ may be recessed a predetermineddistance from one surface of the second body part 821′ facing the secondinsertion part 823′. That is, in this embodiment, the second pincoupling part 825′ may not be formed through the second body part 821′and the second protrusion part 822′.

The second pin 440 b may be movably inserted into the second pincoupling part 825′. That is, while the second pin 440 b is inserted intothe second pin coupling part 825′, the second balance weight 820′ maymove a predetermined distance lengthwise, that is, in the front-reardirection in the shown embodiment.

When the second balance weight 820′ is moved lengthwise toward theexpansion part 700, the refrigerant communication flow path 450 maycommunicate with the second back pressure chamber 521. On the contrary,when the second balance weight 820′ is moved lengthwise toward therotary shaft part 400 and the second body part 821′ is brought intocontact with the end portion of the second end 420, the refrigerantcommunication flow path 450 and the second back pressure chamber 521 maynot communicate with each other.

A closed surface 827 may form one surface of the second protrusion part822′. In detail, the closed surface 827 may form one surface of thesecond protrusion part 822′ opposite to the second body part 821′.

When the second balance weight 820′ is coupled to the second end 420 bythe second pin 440 b, the closed surface 827 may be configured tosurround the second pin 440 b facing the expansion part 700.Accordingly, it may be possible to ensure the blocking of communicationbetween the refrigerant communication flow path 450 and the second backpressure chamber 521.

Also, a second communication part 826′ may not be formed in the secondbalance weight 820′ according to this embodiment. That is, thecommunication between the refrigerant communication flow path 450 andthe second back pressure chamber 521 may be adjusted by the second bodypart 821′ and the closed surface 827.

The flow of refrigerant according to the embodiments will be describedlater.

The air conditioning system 1 according to an embodiment of the presentdisclosure may be configured to cool or heat air through heat exchangewith refrigerant.

Referring to FIGS. 8 to 11, the air conditioning system 1 according toan embodiment of the present disclosure may comprise an air conditioningpart 900 in addition to the above-described electric compression andexpansion apparatus 10.

The air conditioning part 900 may be configured such that refrigerantcompressed or expanded by the electric compression and expansionapparatus 10 exchanges heat with air. The air having exchanged heat withthe refrigerant may be cooled or heated according to a user's request.

The air conditioning part 900 may comprise a compressed-refrigerant flowpath 910, a condensed-refrigerant flow path 920, an expanded-refrigerantflow path 930, an evaporated-refrigerant flow path 940, a condenser 950,and an evaporator 960.

The compressed-refrigerant flow path 910 may fluidly connect theelectric compression and expansion apparatus 10 to the condenser 950. Indetail, the compressed-refrigerant flow path 910 may be a passagethrough which refrigerant compressed in the compression part 600 of theelectric compression and expansion apparatus 10 flows toward thecondenser 950.

The compressed-refrigerant flow path 910 may communicate with theexhaust port 212 of the electric compression and expansion apparatus 10.The compressed refrigerant may be discharged through the exhaust port212 and introduced into the condenser 950.

The condensed-refrigerant flow path 920 may connect the electriccompression and expansion apparatus 10 to and in fluid communicationwith the expansion apparatus 10. In detail, the condensed-refrigerantflow path 920 may be a passage through which high-pressure refrigerantcondensed in the condenser 950 flows toward the expansion part 700 ofthe electric compression and expansion apparatus 10.

The condensed-refrigerant flow path 920 may communicate with therefrigerant intake opening 724 of the electric compression and expansionapparatus 10. The refrigerant condensed in the condenser 950 may bemoved to and expanded in the expansion part 700 of the electriccompression and expansion apparatus 10.

The expanded-refrigerant flow path 930 may connect the electriccompression and expansion apparatus 10 to and in fluid communicationwith the evaporator 960. In detail, the expanded-refrigerant flow path930 may be a passage through which refrigerant expanded in the expansionpart 700 of the electric compression and expansion apparatus 10 flowstoward the evaporator 960.

The expanded-refrigerant flow path 930 may communicate with therefrigerant discharge opening 726 of the electric compression andexpansion apparatus 10. The refrigerant expanded in the expansion part700 may be discharged and flows toward the evaporator 960.

The evaporated-refrigerant flow path 940 may connect the evaporator 960to and in fluid communication with the electric compression andexpansion apparatus 10. In detail, the evaporated-refrigerant flow path940 may be a passage through which low-pressure refrigerant evaporatedin the evaporator 960 flows toward the compression part 600 of theelectric compression and expansion apparatus 10.

The evaporated-refrigerant flow path 940 may communicate with the intakeport 120 of the electric compression and expansion apparatus 10. Therefrigerant evaporated in the evaporator 960 may be moved to andcompressed in the compression part 600 of the electric compression andexpansion apparatus 10.

The refrigerant compressed in the compression part 600 of the electriccompression and expansion apparatus 10 may be introduced into thecondenser 950. The condenser 950 may communicate with the compressionpart 600 of the electric compression and expansion apparatus 10 by meansof the compressed-refrigerant flow path 910.

The condenser 950 may be configured to enable heat exchange between airand compressed high-temperature high-pressure refrigerant to heat theair. The refrigerant having exchanged heat with the air may be changedto a high-pressure low-temperature state.

The high-pressure low-temperature refrigerant may be introduced into andexpanded in the expansion part 700 of the electric compression andexpansion apparatus 10. The condenser 950 may communicate with theexpansion part 700 of the electric compression and expansion apparatus10 by means of the condensed-refrigerant flow path 920.

The refrigerant expanded in the expansion part 700 of the electriccompression and expansion apparatus 10 may be introduced into theevaporator 960. The evaporator 960 may communicate with the expansionpart 700 of the electric compression and expansion apparatus 10 by meansof the expanded-refrigerant flow path 930.

The evaporator 960 may be configured to enable heat exchange between airand expanded compressed low-temperature low-pressure refrigerant to heatthe refrigerant. The refrigerant having exchanged heat with the air maybe changed to a high-temperature low-pressure state.

That is, the air conditioning system 1 of the present disclosure may beconfigured such that refrigerant circulates through the compression part600 of the electric compression and expansion apparatus 10, thecondenser 950, the expansion part 700 of the electric compression andexpansion apparatus 10, and the evaporator 960 to exchange heat withair.

With the electric compression and expansion apparatus 10 according to anembodiment of the present disclosure, it may be possible to perform bothcompression and expansion of refrigerant in a single apparatus. That is,the electric compression and expansion apparatus 10 may comprise thecompression part 600 for compressing refrigerant and the expansion part700.

The first back pressure chamber 511 may be formed in the first mainframe 510 adjacent to the compression part 600. Also, the second backpressure chamber 521 may be formed in the second main frame adjacent tothe expansion part 700. Some of the compressed refrigerant or theexpanded refrigerant may be introduced into the back pressure chambers511 and 521 to form back pressure.

The electric compression and expansion apparatus 10 according to anembodiment of the present disclosure may enable the first back pressurechamber 511 and the second back pressure chamber 521 to communicate witheach other by means of the refrigerant communication flow path 450 ofthe rotary shaft part 400.

In this case, the refrigerant may travel in a direction from the firstback pressure chamber 511 to the second back pressure chamber 521 whilethe refrigerant should not travel in a direction from the second backpressure chamber 521 to the first back pressure chamber 511.

This may be because when the electric compression and expansionapparatus 10 is driven, the stable operation of the compression part 600for compressing refrigerant is of great importance. When a back pressureinside the first back pressure chamber 511 changes due to refrigerantintroduced from the second back pressure chamber 521, the stable drivingof the electric compression and expansion apparatus 10 may becomedifficult.

Accordingly, the electric compression and expansion apparatus 10according to an embodiment of the present disclosure may be configuredto adjust the flow of refrigerant to be formed in only a direction fromthe first back pressure chamber 511 to the second back pressure chamber521. The adjustment may be achieved by the check valve 830 and thesecond balance weight 820′.

The process of adjusting the flow of refrigerant between the backpressure chambers 511 and 512 in the electric compression and expansionapparatus 10 according to an embodiment of the present disclosure willbe described in detail below with reference to FIGS. 8 to 11.

The process of adjusting a flow of refrigerant by means of the checkvalve 830 will be described with reference to FIGS. 8 and 9.

FIG. 8 shows that the check valve 830 is open and the flow path of therefrigerant is formed in a direction from the first back pressurechamber 511 toward the second back pressure chamber 521.

In the shown state, a back pressure formed by refrigerant staying in thefirst back pressure chamber 511 may be greater than a back pressureformed by refrigerant staying in the second back pressure chamber 521.

Due to the difference between the back pressures, the refrigerant mayflow out of the first back pressure chamber 511 and flow into therefrigerant communication flow path 450 through the first communicationpart 816 of the first balance weight 810.

The check valve 830 may be configured to allow flow only when thepressure of the first back pressure chamber 511 is higher than that ofthe second back pressure chamber 521. Since the shown situation meets acondition for the check valve 830 to open, the check valve 830 may beopen.

Thus, the refrigerant introduced into the refrigerant communication flowpath 450 may be moved to the expansion part 700 via the check valve 830.

The second communication part 826 communicating with the second backpressure chamber 521 and the refrigerant communication flow path 450 maybe formed in the second balance weight 820 coupled to the second end 420of the rotary shaft part 400. The refrigerant may flow to the secondback pressure chamber 521 through the second communication part 826.

Accordingly, the refrigerant may communicate between the first backpressure chamber 511 and the second back pressure chamber 521 and theback pressures of the back pressure chambers 511 and 521 may be shared.

As a result, the back pressure formed by operation of the compressionpart 600 may be formed in the second back pressure chamber 521.Furthermore, the compression part 600 and the expansion part 700 may beoperated by the same motor part 300.

Accordingly, the expansion part 700 may operate to correspond to theoperation of the compression part 600, and thus it may be possible toimprove expansion efficiency.

FIG. 9 shows that the check valve 830 is closed and the communicationbetween the first back pressure chamber and the second back pressurechamber is blocked. In the shown state, a back pressure formed byrefrigerant staying in the first back pressure chamber 511 may besmaller than or equal to a back pressure formed by refrigerant stayingin the second back pressure chamber 521.

Due to the difference between the back pressures, the refrigerant mayflow out of the second back pressure chamber 521 and flow into therefrigerant communication flow path 450 through the second communicationpart 826.

In this case, the check valve 830 may be configured to open only whenthe back pressure of the first back pressure chamber 511 is greater thanthe back pressure of the second back pressure chamber 521. Accordingly,in the shown embodiment, the check valve 830 may be closed to preventthe refrigerant of the second back pressure chamber 521 from flowingtoward the first back pressure chamber 511.

Therefore, the back pressure caused by the refrigerant staying in thefirst back pressure chamber 511 may not be disturbed by the refrigerantstaying in the second back pressure chamber 521. As a result, theoperation of the compression part 600 may be stably performed, and thusit may be possible to improve compression efficiency.

The process of adjusting a flow of refrigerant by means of the secondbalance weight 820′ will be described with reference to FIGS. 11 and 12.

FIG. 10 shows that the second balance weight 820′ may move apredetermined distance toward the expansion part 700 so that arefrigerant flow path is formed in a direction from the first backpressure chamber 511 to the second back pressure chamber 521.

In the shown state, a back pressure formed by refrigerant staying in thefirst back pressure chamber 511 may be greater than a back pressureformed by refrigerant staying in the second back pressure chamber 521.

Due to the difference between the back pressures, the refrigerant mayflow out of the first back pressure chamber 511 and flow into therefrigerant communication flow path 450 through the first communicationpart 816 of the first balance weight 810.

The second balance weight 820′ may move a predetermined distance towardthe expansion part 700 by a hydraulic pressure generated by therefrigerant that has flowed in the refrigerant communication flow path450 and that moves from one side facing the compression part 600 to theother side facing the expansion part 700.

Accordingly, the refrigerant communication flow path 450 may communicatewith the second back pressure chamber 521. As a result, the refrigeranthaving flown out of the first back pressure chamber 511 may beintroduced into the second back pressure chamber 521 through therefrigerant communication flow path 450.

Accordingly, the refrigerant may communicate between the first backpressure chamber 511 and the second back pressure chamber 521 and theback pressures of the back pressure chambers 511 and 521 may be shared.

As a result, the back pressure formed by operation of the compressionpart 600 may be formed in the second back pressure chamber 521.Furthermore, the compression part 600 and the expansion part 700 may beoperated by the same motor part 300.

Accordingly, the expansion part 700 may operate to correspond to theoperation of the compression part 600, and thus it may be possible toimprove expansion efficiency.

FIG. 11 shows that the second balance weight 820′ may be coupled to andin close contact with one side of the rotary shaft part 400 facing theexpansion part 700, that is, the end surface of the second end 420.

In the shown state, an opening of the refrigerant communication flowpath 450 facing the expansion part 700 may be closed by the second bodypart 821′ of the second balance weight 820′.

Due to the difference between the back pressures, the refrigerant mayflow out of the second back pressure chamber 521 and move in a directiontoward the second communication part 826.

In this case, the second balance weight 820′ may be axially movablycoupled to the second pin 440 b. A hydraulic pressure formed by the flowof the refrigerant may move the second balance weight 820′ toward therotary shaft part 400.

As described above, a separate second communication part 826 may not beformed in the second balance weight 820′ according to this embodiment.Accordingly, when the second body part 821′ is in close contact with thesecond end 420, the opening of the refrigerant communication flow path450 formed at the second end 420 may be closed by the second balanceweight 820′.

Accordingly, the refrigerant having stayed in the second back pressurechamber 521 may not be introduced into the refrigerant communicationflow path 450 because the refrigerant communication flow path 450 may beclosed. As a result, the communication between the second back pressurechamber 521 and the first back pressure chamber 511 may be blocked.

Therefore, the back pressure caused by the refrigerant staying in thefirst back pressure chamber 511 may not be disturbed by the refrigerantstaying in the second back pressure chamber 521. As a result, theoperation of the compression part 600 may be stably performed, and thusit may be possible to improve compression efficiency.

The electric compression and expansion apparatus 10 according to anembodiment of the present disclosure may comprise both the compressionpart 600 and the expansion part 700. The compression part 600 and theexpansion part 700 may be partially housed in the first main frame 510and the second main frame 520, respectively.

Accordingly, the main housing 100 may just have a space for housing themotor part 300 formed therein, and thus the size of the main housing 100may be reduced.

Also, the first fixed scroll 620 of the compression part 600 and thesecond fixed scroll 720 of the expansion part 700 may be exposed to theoutside. Accordingly, the first main frame 510 and the second main frame520 may not require spaces for housing the fixed scrolls 620 and 720.

Therefore, it may be possible to perform both compression and expansionof refrigerant in a sing apparatus, and it may also be possible tominimize the electric compression and expansion apparatus 10.

The air conditioning system 1 may comprise the condenser 950 and theevaporator 960. Also, an element of the air conditioning system 1 forcompressing and expanding refrigerant may be implemented by the singleelectric compression and expansion apparatus 10.

As described above, the electric compression and expansion apparatus 10according to an embodiment of the present disclosure can be minimizedwhile being configured to perform both compression and expansion ofrefrigerant.

Accordingly, the volume of the air conditioning system 1 including theelectric compression and expansion apparatus 10 may be reduced.Accordingly, a large space may not be required when the air conditioningsystem 1 is provided in vehicles, refrigerators needing airconditioning, and clothing processing apparatuses.

The first orbiting scroll 610 of the compression part 600 and the secondorbiting scroll 710 of the expansion part 700 may be coupled to thesample rotary shaft part 400. When the motor part 300 is operated, therotary shaft part 400, the first orbiting scroll 610, and the secondorbiting scroll 710 may be configured to rotate together.

Therefore, a rate at which the refrigerant is compressed in thecompression part 600 and a rate at which the refrigerant is expanded inthe expansion part 700 may be interoperable. Accordingly, it may bepossible to improve the air conditioning efficiency of the airconditioning system.

The first orbiting scroll 610 of the compression part 600 and the secondorbiting scroll 710 of the expansion part 700 may be driven by thesingle motor part 300 connected to the rotary shaft part 400.

Therefore, since a separate power source for driving the compressionpart 600 and the expansion part 700 is not required, it may be possibleto improve the power efficiency of the electric compression andexpansion apparatus 10.

The refrigerant communication flow path 450 may be formed through therotary shaft part 400. The refrigerant communication flow path 450 maycommunicate with the first back pressure chamber 511 at the compressionpart 600 side and the second back pressure chamber 521 at the expansionpart 700 side.

Accordingly, when the compression of the refrigerant in the compressionpart 600 is being performed, a back pressure generated in the first backpressure chamber 511 may be delivered to the second back pressurechamber 521 through the refrigerant communication flow path 450. Thismay be achieved by refrigerant flowing from the first back pressurechamber 511 to the second back pressure chamber 521.

Therefore, the high back pressure generated in the compression part 600may be quickly formed in the second back pressure chamber 521.Accordingly, it may be possible to improve expansion efficiency at whichthe expansion part 700 expands refrigerant.

In an embodiment, the check valve 830 may be provided in the refrigerantcommunication flow path 450. The check valve 830 may be configured toallow the flow of refrigerant only when the back pressure of the firstback pressure chamber 511 is higher than that of the second backpressure chamber 521.

That is, refrigerant may move from the first back pressure chamber 511to the second back pressure chamber 521 when the back pressure of thefirst back pressure chamber 511 is higher than the back pressure of thesecond back pressure chamber 521. On the contrary, the flow ofrefrigerant may be blocked when the back pressure of the first backpressure chamber 511 is lower than the back pressure of the second backpressure chamber 521.

In another embodiment, the second balance weight 820′ may move apredetermined distance in an axial direction of the second pin 440 b toopen or close the refrigerant communication flow path 450 at the secondend 420 side.

That is, when the back pressure of the first back pressure chamber 511is higher than the back pressure of the second back pressure chamber521, the second balance weight 820′ may move a predetermined distancetoward the expansion part 700. Accordingly, the refrigerantcommunication flow path 450 may communicate with the second backpressure chamber 521, and thus the refrigerant staying in the first backpressure chamber 511 may be introduced into the second back pressurechamber 521.

On the contrary, when the back pressure of the first back pressurechamber 511 is lower than the back pressure of the second back pressurechamber 521, the second balance weight 820′ may move a predetermineddistance toward the second end 420. Thus, the refrigerant communicationflow path 450 may be closed, and thus the communication between thefirst back pressure chamber 511 and the second back pressure chamber 521may be blocked.

Therefore, the back pressure of the first back pressure chamber 511 mayaffect the back pressure of the second back pressure chamber 521, butthe back pressure of the second back pressure chamber 521 may not affectthe back pressure of the first back pressure chamber 511. Accordingly,the stable operation of the compression part 600 may be possible, andalso it may be possible to improve the compression efficiency ofrefrigerant.

The foregoing description has been given of the preferred embodiments,but it will be apparent to those skilled in the art that variousmodifications and variations can be made in the present disclosurewithout departing from the spirit or scope of the disclosure as definedin the appended claims.

What is claimed is:
 1. An electric compression and expansion apparatuscomprising: a main housing comprising a motor chamber; a motor parthoused in the motor chamber; a rotary shaft part extending in a lengthdirection and coupled to the motor part, wherein the rotary shaft partis configured to rotate integrally with the motor part; a compressionpart coupled to one side of the rotary shaft part in the lengthdirection, wherein the compression part is configured to rotateintegrally with the rotary shaft part to compress refrigerant; and anexpansion part coupled to another side of the rotary shaft part in thelength direction, wherein the expansion part is configured to rotateintegrally with the rotary shaft part to expand the compressedrefrigerant.
 2. The electric compression and expansion apparatus ofclaim 1, wherein: the main housing comprises an intake port configuredto introduce the refrigerant into the main housing, and a rear housingcomprising an exhaust port located on one side of the compression partopposite to the main housing, the exhaust port being configured todischarge the compressed refrigerant.
 3. The electric compression andexpansion apparatus of claim 1, wherein, the compression part comprises:a first orbiting scroll coupled to the rotary shaft part and configuredto rotate integrally with the rotary shaft part; and a first fixedscroll located on one side of the first orbiting scroll opposite to themain housing, wherein the first fixed scroll is configured to be broughtinto contact with the first orbiting scroll with a predetermined spaceformed therein, and wherein the first fixed scroll is configured tocompress the refrigerant, the expansion part comprises: a secondorbiting scroll coupled to the rotary shaft part and configured torotate integrally with the rotary shaft part; and a second fixed scrolllocated on one side of the second orbiting scroll opposite to the mainhousing, wherein the second fixed scroll is configured to be broughtinto contact with the second orbiting scroll with a predetermined spaceformed therein, and wherein the second fixed scroll is configured toexpand the compressed refrigerant, and the second fixed scroll comprisesan intake hole configured to introduce the compressed refrigerant intothe predetermined space.
 4. The electric compression and expansionapparatus of claim 1, further comprising: a first main frame locatedbetween the main housing and the compression part, the first main framebeing configured to couple the main housing to and in fluidcommunication with the compression part; and a second main frame locatedbetween the main housing and the expansion part, the second main framebeing configured to support another side of the rotary shaft part facingthe expansion part.
 5. The electric compression and expansion apparatusof claim 4, wherein: the first main frame comprises a first bearingsurrounding an outer circumference on one side of the rotary shaft partfacing the compression part, the first bearing being configured tosupport the one side of the rotary shaft part, the second main framecomprises a second bearing surrounding the outer circumference on theanother side of the rotary shaft part facing the expansion part, thesecond bearing being configured to support the another side of therotary shaft part, and the first bearing has a smaller inner diameterthan the second bearing.
 6. The electric compression and expansionapparatus of claim 4, wherein: a refrigerant communication flow path isformed through the rotary shaft part in the length direction, one sideof the refrigerant communication flow path facing the compression partis in communication with an inner space of the first main frame, andanother side of the refrigerant communication flow path facing theexpansion part is in communication with an inner space of the secondmain frame.
 7. The electric compression and expansion apparatus of claim6, wherein the first main frame comprises a first balance weightconfigured to rotate together with the rotary shaft part and thecompression part, wherein one side of the first balance weight iscoupled to one end of the rotary shaft part facing the compression partand another side of the first balance weight opposite to the one side iscoupled to the compression part.
 8. The electric compression andexpansion apparatus of claim 7, wherein: the first balance weightcomprises: a first body part comprising one side configured to bebrought into contact with one end of the rotary shaft part; a firsteccentric part extending from the first body part; and a first spacepart formed through the first body part, wherein a first fastening pinfor coupling the first balance weight to the one end of the rotary shaftis configured to be inserted into the first space part, and the one sideof the first body part comprises a first communication hole recessed andconfigured to form a space to enable the inner space of the first mainframe and the refrigerant communication flow path to communicate witheach other.
 9. The electric compression and expansion apparatus of claim6, wherein a second balance weight is located inside the second mainframe, the second balance weight being configured to rotate togetherwith the rotary shaft part and the expansion part, and wherein one sideof the second balance weight is coupled to another end of the rotaryshaft part facing the expansion part and the another side coupled to theexpansion part and opposite to the one side.
 10. The electriccompression and expansion apparatus of claim 9, wherein the refrigerantcommunication flow path comprises a check valve configured to restrict aflow of refrigerant inside the refrigerant communication flow path to adirection from the first main frame to the second main frame.
 11. Theelectric compression and expansion apparatus of claim 10, wherein: thesecond balance weight comprises: a second body part having one sideconfigured to be brought into contact with the another end of the rotaryshaft part; and a second eccentric part extending from the second bodypart, and the one side of the second body part comprises a secondcommunication hole recessed and configured to form a space to enable theinner space of the second main frame and the refrigerant communicationflow path to communicate with each other.
 12. The electric compressionand expansion apparatus of claim 9, wherein: the second balance weightcomprises: a second body part having one side configured to be broughtinto contact with the another end of the rotary shaft part; a secondprotrusion part protruding a predetermined distance from the anotherside of the second body part opposite to the one side of the second bodypart; and a second eccentric part extending from the second body part,and the second protrusion part comprises: a second space part recessed apredetermined distance from the one side of the second body part,wherein a second fastening pin for coupling the protrusion part to theother end of the rotary shaft part is configured to be inserted into thesecond space part; and a closed surface located on one side of thesecond protrusion part opposite to the one side of the second body part,the closed surface being configured to close the second space part. 13.The electric compression and expansion apparatus of claim 12, wherein:when the pressure in the first main frame is greater than or equal tothe pressure in the second main frame, the second balance weight isconfigured to move a predetermined distance toward the expansion partsuch that the refrigerant communication flow path communicates with theinner space of the second main frame, and when the pressure in the firstmain frame is smaller than the pressure in the second main frame, thesecond balance weight is configured to move a predetermined distancetoward the main housing such that the communication between therefrigerant communication flow path and the inner space of the secondmain frame is blocked.
 14. An air conditioning system comprising: anelectric compression and expansion apparatus configured to be driven bypower and configured to compress or expand refrigerant; a condensercoupled to and in fluid communication with the electric compression andexpansion apparatus, the condenser being configured to condenserefrigerant compressed in the electric compression and expansionapparatus; and an evaporator coupled to and in fluid communication withthe electric compression and expansion apparatus, the evaporator beingconfigured to evaporate refrigerant expanded in the electric compressionand expansion apparatus, wherein the electric compression and expansionapparatus comprises: a main housing comprising a motor chamber; a motorpart housed in the motor chamber; a rotary shaft part extending in alength direction and coupled to the motor part, wherein the rotary shaftpart is configured to rotate integrally with the motor part; acompression part coupled to one side of the rotary shaft part in thelength direction, wherein the compression part is configured to rotateintegrally with the rotary shaft part to compress refrigerant; and anexpansion part coupled to another side of the rotary shaft part in thelength direction, wherein the expansion part is configured to rotateintegrally with the rotary shaft part to expand the compressedrefrigerant.
 15. The air conditioning system of claim 14, wherein: theelectric compression and expansion apparatus comprises: a first mainframe located between the main housing and the compression part, thefirst main frame being configured to couple the main housing to and influid communication with the compression part; and a second main framelocated between the main housing and the expansion part, the second mainframe being configured to support the other side of the rotary shaftpart facing the expansion part, a refrigerant communication flow path isformed through the rotary shaft part in the length direction thereof,one side of the refrigerant communication flow path facing thecompression part is in communication with an inner space of the firstmain frame, and another side of the refrigerant communication flow pathfacing the expansion part is in communication with an inner space of thesecond main frame.
 16. The electric compression and expansion apparatusof claim 2, wherein the intake port comprises a through-hole passingthrough an outer circumferential surface of the main housing.
 17. Theelectric compression and expansion apparatus of claim 2, furthercomprising a discharge chamber formed on one side of the rear housing,wherein the discharge chamber comprises a space through which thecompressed refrigerant passes before being discharged through theexhaust port.
 18. The electric compression and expansion apparatus ofclaim 3, wherein the first fixed scroll comprises: a first fixed endplate part located adjacent to the rear housing; a first fixed wrapcoupled to the first orbiting scroll with a space formed therebetween; adischarge port; and a discharge valve configured to open or close thedischarge port.
 19. An electric compression and expansion apparatuscomprising: a main housing comprising a motor chamber, a firstthrough-hole configured to introduce a refrigerant into the mainhousing; a motor part housed in the motor chamber; a rotary shaft partextending in a length direction and coupled to the motor part, whereinthe rotary shaft part is configured to rotate integrally with the motorpart; a compression part coupled to one side of the rotary shaft part inthe length direction, wherein the compression part is configured torotate integrally with the rotary shaft part to compress therefrigerant; and an expansion part coupled to another side of the rotaryshaft part in the length direction, wherein the expansion part isconfigured to rotate integrally with the rotary shaft part to expand thecompressed refrigerant; and a rear housing comprising a secondthrough-hole located on one side of the compression part opposite to themain housing, the second through-hole being configured to discharge thecompressed refrigerant.
 20. The electric compression and expansionapparatus of claim 19, further comprising: a first main frame locatedbetween the main housing and the compression part, the first main framebeing configured to couple the main housing to the compression part; anda second main frame located between the main housing and the expansionpart, the second main frame being configured to support another side ofthe rotary shaft part facing the expansion part.